Eclipse error 'UseStringDeduplication' - eclipse

I installed a fresh Ubuntu 16.04 VM, Oracle JDK 7, and downloaded the latest Eclipse. But I am getting this error when I try to start Eclipse:
Unrecognized VM option 'UseStringDeduplication'
Error: Could not create the Java Virtual Machine.
Error: A fatal exception has occurred. Program will exit.
Gtk-Message: GtkDialog mapped without a transient parent. This is discouraged.
Why am I getting this error on a fresh install? And is it a bad idea to remove that VM option?

Latest version of Eclipse (Neon) requires Java 8 runtime, and the Eclipse website obnoxiously neglects to mention it anywhere from the homepage to the download link for Eclipse, not even a version warning at runtime for Eclipse.

Same error for me in Kubuntu 14.04, eclipse Neon,
I Removed -XX:+UseStringDeduplication from .ini file, it works for me

I know, i'm little to late to the party. I got this issue lately on my Mac. I updated my eclipse (from Mars to Oxygen) all of the sudden i couldn't start my old project. First i thought, this must have something to do with the new eclipse, which wasn't all wrong. Because eclipse.ini file of Oxygen expected java-1.8.
I updated my java to latest (jdk1.8.0_152.jdk), but the problem remained, than i removed these parameters from the eclipse.ini, still was the same, i checked the "Run Configurations" and basically removed the same parameters from the arguments list. Now my projects seem to work just fine. I also needed to restore the platform, since Oxygen use e.4-platform.
Remove these parameters from eclipse.ini file
Select the project and go to "Run As"->"Run Configurations..."-> "Arguments" check the old configurations under "VM arguments" (it can be a product in case of an RCP-project)
removed the VM-option(s)(actually, they can be more) not recognized and "Apply"-> "Run".

I got the same error when I have installed Java 8 and Java 9 in my Ubuntu 16.04. My eclipse version was Neon. As https://wiki.eclipse.org/Eclipse/Installation#Eclipse_4.6_.28Neon.29 describes to start specific eclipse ide you need relevant JDK. For neon, it was Java 8. Since I installed Java 9 using apt-get it was the default JDK. so I have to change the default JDK to Java 8.
You can check which java version used in system-wide with
java -version
`If you want to see which are the versions of JDK installed in Ubuntu then run below command in shell.
sudo update-java-alternatives --list
Then choose which version you want to set. After that run below command.
sudo update-java-alternatives --set [JDK/JRE name e.g. java-8-oracle]
Now run again Eclipse. if the version was the reason to conflict, it will run now. Referred by http://menukanows.com/how-to-set-a-default-jdk-version-in-ubuntu/

String Deduplication – A new feature in Java 8 Update 20
It means you should nt java 1.8 updated later or equal 20.

I faced the same issue on Eclipse Oxygen in Ubuntu.
Tried:
Checking java version (It was already at 1.8.0 so according to the accepted answer, it should work.)
Removing -XX:+UseStringDeduplication from .ini file
Still didn't solve the problem. Then I saw #simgineer's comment:
In my case this was for eclipse oxygen. I had an older version of java
8 installed (jdk1.8.0_05) when I upgraded to the latest (jdk1.8.0_151)
and updated my eclipse.ini to point to the latest as well (since it is
recorded in there during installation) eclipse oxygen started working.
Solution:
Updated JDK from 1.8.0 to jdk1.8.0_231 and it got resolved.
Voila! I didn't have to update anything in my eclipse.ini .

Related

version 1.7 of the jvm is not suitable for this product. version 1.8 greater is required for eclipse nano in window

I am trying to launch Eclipse Nano in Windows 7, but getting the error:
Version 1.7 of the JVM is not suitable for this product. version 1.8 greater is required for Eclipse Nano in Windows
I already have Java 8 installed on the system
Simply download 1.8 JDK from Java SE Development Kit 8 Downloads install it, then copy the jre folder & paste it in:
"C:\Program Files (x86)\EclipseNeon\"
Then rename the folder to "jre", start the eclipse again it should work.
sudo /usr/sbin/update-alternatives --config java
and select the jvm 1.8
I faced the same issue (Windows 10). You need to set the "JAVA_HOME" system environment variable to point to JDK 8 folder and edit the "Path" system environment variable to have a new path to JRE 8's bin folder, this should be at the top of the list.
I too got the same error while installing
Possible reason for the error - The eclipse version, you are installing and the Java version should be of same bit, i.e. either 32 bit or 64 bit
Solution: I have downloaded both the java for 64 bit and 32 bit and installed, now my problem is gone.
Please let me know if it works for you.
When you download the latest eclipse, and extract it, you can find the folder named eclipse-installer with eclipse-inst file inside it. Instead of double-clicking it to start installation, just navigate to the folder in terminal and run ./eclipse-inst command. It does the entire installation for you. It worked for me and hope who also got the same problem(version 1.7 of the jvm is not suitable for this product. version 1.8 greater is required) gets solved. :)
On a Windows system I had the same problem.
Although I had only Java 1.8 installed, I found that I also had a 1.7 upgrade file installed too (which didn't get uninstalled automatically when I installed 1.8).
Uninstalling this upgrade file allowed me to install Eclipse IDE.
I had the same issue and I had a different solution to this problem.
Though I set the JAVA_HOME to 1.8 (Both through CMD and environment variables), the error was persisting.
So I opened CMD prompt, typed:
java - version
to find out 1.7 was the version my system was set to. Until then I had no clue from where it was fetching this version.
And then I changed it to 1.8 using this command:
set path=C:\.....eclipse\jdk1.8.0_141-b15\bin
AND IT WORKED!
Recheck if it is set to 1.8 with the same command:
java -version
You should be good to go now!
if it's a 64-bit Eclipse. You'll need to explicitly download and install the 64-bit Java 8 or later.
download it from here
http://www.oracle.com/technetwork/java/javase/downloads/jdk8-downloads-2133151.html
tips for windows users
Version 1.7 of the JVM is not suitable for this product. version 1.8
greater is required
user get above error message because they had multiple jdk version or they do not have latest version of jdk installed , even if you install latest version of jdk and you if you have not removed old version of jdk like 1.7 you will get the above error message , so better to get rid of old version of jdk and jre etc.
-> ignore this step if you have insallted latest version of jdk already
download 32 or 64 bit latest jdk from : https://www.oracle.com/technetwork/java/javase/downloads/jdk8-downloads-2133151.html
-> go to C:\Program Files\Java and look for old version of jdk , let say if you have 1.7 versions of jdk delete them so that you are left only with latest version , you can remove old versions of jre too here just by deleting.
-> next run eclipse you will not get v1.7 message
Find the JVM
If a JVM is installed in the eclipse/jre directory, Eclipse will use it; otherwise the launcher will consult the eclipse.ini file and the system path variable. Eclipse DOES NOT consult the JAVA_HOME environment variable.
To explicitly specify a JVM of your choice, you can use the -vm command line argument:
eclipse -vm c:\jre\bin\javaw.exe ''start Java by executing the specified java executable
eclipse -vm c:\jre\bin\client\jvm.dll ''start Java by loading the jvm in the eclipse process
Go to Eclipse directory, find and open eclipse.ini configuration file then modify below parameter to your desired version, it will work.
-Dosgi.requiredJavaVersion=1.8
It worked for me
Eclipse will consider the version that is mentioned in eclipse.ini file, this error
means that your installed java version (in environment variable) and the mentioned java
version in eclipse.ini file is not matching.
You may just change the java version there (it will be in eclipse-installation-dir).
Change the property as below:-
-Dosgi.requiredJavaVersion=
Updating below line in eclipse.ini worked for me
-Dosgi.requiredJavaVersion=1.8
Two things:
Check this question here as it's similar and has some good pointers Eclipse - no Java (JRE) / (JDK) ... no virtual machine
Also, get the latest JRE and JDK from Oracle vs from java.com http://www.oracle.com/technetwork/java/javase/downloads/index.html
Today I meet the same question. I download the file that named "eclipse-inst-linux64.tar.gz". When I open the eclipse, it shows "Version 1.7.0_121 of the JVM is not suitable for this product. Version: 1.8".Then execute
cd /usr/bin/
sudo ln -s /Your_JAVA_PATH /usr/bin/java
Then you can install eclipse.
Make sure java and eclipse versions are same(32bit or 64bit)
Try running eclipse-installer as administrator(this worked for me)
If you need to skip this step just simply change Required Version number, ex:
open with any text editor instalation path/AptanaStudio3.ini
and change
-Dosgi.requiredJavaVersion=1.8 to -Dosgi.requiredJavaVersion=1.7
This is just for skipping this step.
I had both 1.7 and 1.8 in path and 1.7 was on top and 1.8 below in Pah, so i moved 1.7 below 1.8, thats it it worked.
Go to Oracle's website and download the newest version of Java JDK. (https://www.oracle.com/java/technologies/javase-downloads.html)
Install the program on your computer.
Remove all old environment variables related to Oracle and Java.
Set the environment variables related to the new installation all the way to the bin folder. (include the bin folder in the environment variables section)

Spring STS 3.7.2 "No Java virtual Machine Found" on Mac OS X Yosemite

I have been using Spring STS 3.7.2 for a few months on my Mac laptop (Mac OS X Yosemite 10.10.5). But suddenly the STS IDE is not starting up. I suspect that one of the automatic OS update may have changed something, since I noticed that I don't see java any more on my path setting.
I manually added the following entries to my .bash_profile and updated using source command:
export PATH=$PATH:/Library/Java/JavaVirtualMachines/jdk1.8.0_65.jdk/Contents/Home/jre/bin
export JAVA_HOME=/Library/Java/JavaVirtualMachines/jdk1.8.0_65.jdk/Contents/Home
But STS stubbornly not working. It keeps giving me the error message in a dialog box:
A java runtime environment (JRE) or Java development kit (JDK) must
be available in order to run STS. No Java virtual machine was found
after searching ....
I am confused. I am able to invoke java from any terminal window, as well as JAVA_HOME environment variable is set.
Any ideas what may be going on?
After quite a bit of searching online, I figured out the problem, and resolved it for myself. It basically boils down to JDK upgrade to versions beyond 1.6.
The following link provided a solution:
https://apple.stackexchange.com/questions/178647/jdk-platform-not-recognized-running-eclipse-or-mvn
Here are the steps:
Revert back to JDK 1.6: Download and install JDK 1.6 from this Apple site: https://support.apple.com/kb/DL1572?locale=en_US
Change the PATH variable to point to the 'bin' directory of where JDK is installed. On my Mac, it was installed at: /Library/Java/JavaVirtualMachines/1.6.0.jdk/Contents/Home/bin
Go to the STS application installed directory and run the command "open -a STS.app". This will open the STS IDE successfully.
Exit STS.
Now, if you want to use Java 8, then change the PATH variable to the Java 8 directory. On my Mac, it was at: /Library/Java/JavaVirtualMachines/jdk1.8.0_65.jdk/Contents/Home/bin
Launch the STS app again, and voila!, the problem solved.

PyDev not showing up in Eclipse

I just installed Eclipse Kepler (after an issue with a faulty update in Juno) and tried to install PyDev using the Install New Software option in Eclipse. Basically just following memory/online tutorials. After installing I can't see it in my Preferences pane. Any ideas why that might be so?
Thanks.
Yes, I have Java 7 installed.
UPDATE: A lot of users have suggested numerous solutions to this problem. There may be more than one correct answer below. See what helps you...
Too much!
After wasting 4 hours trying to install PyDev 3, I moved back to 2.8.2 and used the drop in technique instead of Add new software and it now works!
Download 2.8.2 from sourceforge
http://sourceforge.net/projects/pydev/files/pydev/
Uninstall PyDev.
Simply unzip the contents into the dropins folder below eclipse.
Restart eclipse.
After struggling with this problem for some days I wanted to share my solution to the problem - inspired by the above posts (kudo's to them).
My Configuration:
MacBook Air (intel) with OS X 10.9
Eclipse: Kepler SR1 installed (zip file extracted in the Applications folder)
My situation:
Tried to install PyDev via Eclipse Help --> Install new software...
Installation was succesfull, but PyDev didn't show up anywhere in Eclipse.
My solution:
In Eclipse go to Help --> Install new software...
Uncheck "Show only the latest versions of available software"
Select PyDev the usual way, but install the latest 2.x version instead of the 3.x version
Apparently PyDev 3.0 does not work with the default OS X configuration of Eclipse, Java and Python (don't exactly know why, though...)
I just figured it out.
You will need JDK rather than a JRE.
Download it here first:JDK Download
Install it.
Explore /Applications/eclipse/Eclipse.app/Contents/MacOS (where you put your Eclipse)
Open eclipse.ini
add
-vm
/Library/Java/JavaVirtualMachines/jdk1.7.0_45.jdk/Contents/Home/bin/java
You will change the version according to your situation.
Enjoy!
It happened to me too, but using Debian stable (wheezy, in my case).
I solved installing doing:
# apt-get install openjdk-7-jdk
After this, I checked that I had two alternatives of Java JDK:
# update-java-alternatives -l
And the output was:
java-1.6.0-openjdk-amd64 1061 /usr/lib/jvm/java-1.6.0-openjdk-amd64
java-1.7.0-openjdk-amd64 1051 /usr/lib/jvm/java-1.7.0-openjdk-amd64
Finally, I did:
# update-java-alternatives -s java-1.7.0-openjdk-amd64
After that, I removed pydev plugin from Eclipse, reboot Eclipse, install pydev (using Marketplace), reboot Eclipse, and now it works.
Credits:
http://vas.davimas.name/2013/07/switching-between-openjdk-v6-and-v7-in.html and Richard's answer, above
Most likely you do not have java 7 or > eclipse 3.7 installed on your machine it is a requirement of pyDev 3 see here http://pydev.blogspot.co.uk/2013/11/pydev-30.html
The PyDev.org website states (http://pydev.org/manual_101_install.html) --
"""
Important requisite
PyDev now requires java 7 in order to run. If you don't have java 7, the update
process may appear to succeed, but PyDev will simply not show in the target
installation. Please double-check if you're using a java 7 vm in
about > installation details > configuration
before trying to install PyDev.
"""
This problem started to appear in my Eclipse after I removed the Java 7 runtime from my system (because the Java code I am building needs to run on an older version of Java, but that's unrelated). After I realized that I had lost PyDev, I reinstalled Java 7 and PyDev is working fine now.
Another option would be to rollback to the previous version of PyDev that does not require Java 7, but it would require a manual installation of PyDev and I would lose the convenience of automated updates. The best way forward, it seems, to run run Eclipse on Java 7 and switch those Java projects that need to depend explicitly on Java 6 to that JDK/JRE.
How I was able to get pydev to work in mac/eclipse is download the latest JDK as mention 100 times above install it and then do the following.
open eclipse choose preferences > java > installed JREs
click on "Search..." button it will auto populate the JDK 1.7 you just installed
Click ok
have a beer!
-Cheers!
Solved.
OSX Mavericks 10.9, Eclipse Keplar 4.3.2, PyDev 3.4
Problem: PyDev not showing up under Ecplise > preferences
Solution: Download, install and point Ecplise to JDK 1.7
Unistall PyDev
Under Eclipse > preferences > Installed JREs you probably only see Java SE 6
Download and install JDK 1.7 from http://www.oracle.com/technetwork/java/javase/downloads/jdk7-downloads-1880260.html
open terminal and run "/usr/libexec/java_home -v 1.7"
this will return the directory in which JDK 1.7 reside, something like /Library/Java/JavaVirtualMachines/jdk1.7.0_55.jdk/Contents/Home
Under Eclipse > preferences > Installed JREs click "add", select "MacOS X VM", click "next"
in JRE Home paste your version of /Library/Java/JavaVirtualMachines/jdk1.7.0_55.jdk/Contents/Home, give it a name and click "Finish"
Restart Eclipse and re-install PyDev.
Voila!
I had the same issue on Luna and found my mistake.
After checking the author in "Do you trust these certificates?" page, and I was able to successfully install pydev.
The page lets you proceed without checking it, and no error occurs and it was where I totally missed. Maybe it is useful for someone.
You can move back to 2.x.x:
Eclipse -> About Eclipse then click "Installation Details" button.
From "Installation History" tab choose last installation.
Click Revert button.
You will go back to chosen installation.
I managed to get the following to work with Eclipse IDE for Java Developers 4.4.1 Luna on OS X 10.9.5 Mavericks:
Download and install the latest version of the JDK (currently Java SE 8u25) from http://www.oracle.com/technetwork/java/javase/downloads/index.html. (Not the JRE!)
Navigate to /Applications/eclipse/Eclipse.app/Contents/MacOS (or wherever you have Eclipse installed) and open eclipse.ini.
Append the following to the bottom of the file (be sure to replace the version number with yours):
-vm
/Library/Java/JavaVirtualMachines/jdk1.8.0_25.jdk/Contents/Home/bin/java
Download the latest version of PyDev (currently 3.8.0) from SourceForge at http://sourceforge.net/projects/pydev/files/pydev/.
Unzip its contents to /Applications/eclipse/dropins (or wherever you have Eclipse installed) and restart Eclipse.
Hope this helps anyone who's still having the issue. Special thanks to Mohammed Lokhandwala and braineo.
Aha , It is solved just now.I show it in the following.
First , I use MyEclipse with jdk1.8,maybe some people dont know that Eclipse (or MyEclipse) has its own jvm , what is not "jdk" you downloaded and installed and the "built-in jvm" is default. You can check this out by clicking like this " Windows-->preferences-->Java-->Installed JREs" And I found my MyEclipse used the default jdk1.6 .Then I click "add" to build path of my installed jdk1.8 .
Second , I opened the configuration file named "myeclipse.ini" and check this in the following.
binary/com.sun.java.jdk.win32.x86_64_1.6.0.u43/bin/javaw.exe
Third , I replaced it with new path . Check the following out. It is new path.
D:/jdk/java/jdk1.8/bin/javaw.exe
Last , restart it .And you can find "PyDev" in "Preference".
Happy Coding with Python!
PS:Pycharm is good,and you can get it for free if you are a student or a teacher. click here
I was experiencing the same problem using java 1.7.0_101.
Updated to 1.8.0_91 and "voilá"! PyDev finally appeared.
After trying all of the listed ways to work with 1.7 I was still seeing error message when Eclipse tried to open the editors and navigators on startup. But when I created a new project it worked. Then I tried just closing all editors and reopening them and they too work. The navigator had also set itself to working set and showed nothing. When I switched that to projects it also started working.
The same thing happened to me. This is how i fixed it.
Click on "install new software" - it's under help.
Click on " what is already installed"
Uninstall PyDev
Reinstall PyDev BUT instead of the 3.3XX version, install the latest 2.XX version (i.e click on the drop down menu and select the latest 2.XX version)
It worked for me!
So I tired many of the suggestion above, and I think what finally got it to work is instal the JDK from: http://www.oracle.com/technetwork/java/javase/downloads/index.html. You might also need to uninstall the pydev plugin and reinstall it again. But after install the JDK 8, I got the Pydev to show up under preference.
menu Help > Install New Software...
don't fill "works with" but click on Add...
In the next screen, add the update site of PyDev and PyDev Extensions:
Name : PyDev and PyDev Extensions
Location: http://pydev.org/updates
and go on...
pydev 3 is buggy! Use 2.8 and you should be fine.
I also had this problem, wanted to use python3.4 as interpreter and it wasn't compatible with pydev 2.8 so after a few trials I found out that if you install pydev 2.5 everything works fine !! (At least on Eclipse Kepler).
I know this thread is old but I thought I might contribute my solution because none of the suggestions above worked for my Mac running Yosemite [10.10.2]. I hope this will be helpful to someone else. Despite updating to the latest JDK my mac kept reporting a wrong version. It turns out the symlink was point to the old version and fixing that issue got my pydev/eclipse working.
Find out the current default Java version
Java -version
Get installed versions
/usr/libexec/java_home -V
Navigate to the following folder and delete the current symlink
cd /System/Library/Frameworks/JavaVM.framework/Versions/
rm CurrentJDK
Create a new symlink pointing it to the newer installation substituting 'new-version' with appropriate version from 2 above. i.e jdk1.8.0_40.jdk
ln -s /Library/Java/JavaVirtualMachines/<new-version>/Contents/ CurrentJDK
Confirm your default version
Java -version
Restart.
Happy coding.. :)
I had to uninstall pyDev 3 and install 2.8 to get this working with Eclipse (V 4.4) and Yosemite (V 10.10)
The easiest way is just getting http://www.liclipse.com/ which has everything setup from the start... if you don't want to go that route (as LiClipse is commercial) you may want to try to specify the java 7 install manually:
Grabbed from http://pydev.org/download.html:
Well, the main issue at this time is that PyDev requires Java 7 in order to run. So, if you don't want to support PyDev by going the LiClipse route (which is mostly a PyDev standalone plus some goodies), you may have to go through some loops to make sure that you're actually using Java 7 to run Eclipse/PyDev (as explained below).
All OSes
Make sure you download/install the latest Java 7 JRE or JDK, try restarting to see if it got it automatically.
I.e.: in help > about > installation details > configuration check if it's actually using the java 7 version you pointed at.
If it didn't get it automatically, follow the instructions from:
http://wiki.eclipse.org/Eclipse.ini to add the -vm argument to eclipse.ini on "Specifying the JVM" to specify the java 7 vm.
Note on Mac OS: You can use the command "/usr/libexec/java_home -v 1.7" to get the base path for the JVM (though you also need to append "/bin/java" to the output of said command to the -vm arg in eclipse.ini).
Solution
Using standard Eclipse installation method:
In Install New Software, Add a new site to Work With. I called my entry PyDev Old and entered the Location:
https://dl.bintray.com/fabioz/pydev/old/site.xml
That has PyDev for Eclipse versions 2.8.2 to 4.5.3
Details
I am working with Indigo (3.7) and so need a version of PyDev that is older than 3.0.0. My JDK is 7 as noted elsewhere in this question. The option for Show only the latest versions of available software is turned off.
The standard advice for getting PyDev is to use http://pydev.org/updates and turn off the only latest option. That now only lists PyDev 5.
I had the same issue!
Just update all three SWs to the latest version and it will solve the problem.
Do like this:
update Eclipse to Luna Service Release 2 (4.4.2) 64-bit, then
PyDev - Python IDE for Eclipse 5.1.2 from Eclipse Marketplace and then
download and update the Java SE Development Kit 8u92 64-bit
It should work well now!
I had the same issue in Eclipse 4.4. Had to use a previous version of PyDev. It simply seems to be a matter of using the correct Java JRE/JDK and PyDev for the version of Eclipse you're running.
From http://www.pydev.org/
Release 5.2.0
Important PyDev now requires Java 8 and Eclipse 4.5 onwards.
PyDev 4.5.5 is the last release supporting Java 7 and Eclipse 3.8.
See: update sites page (http://www.pydev.org/update_sites/index.html) for the update site of older versions of PyDev.
Oct 2016:
Installed fresh new copy of Java JDK 1.8.0_102 took care of the incompatible OSX JRE 1.6
Installed fresh copy of Eclipse Neon 4.6.1
Followed pydev manual: http://www.pydev.org/manual_101_install.html
all working fine now...
First install and setup following applications as these are mentioned in above answers:
Jave (version 8 or greater)
Eclipse(version Neon/Oxygen or greater)
PyDev in Eclipse
Now go through following steps:
Eclipse -> Window -> Perspective -> Open Perspective -> Other..
Select PyDev in the list.
Click Open.
Now you are all set.
Cheers!!!
Make sure you install the 64-bit version of Eclipse if you can. If so you should be able to use the latest version of Pydev without any problem.

PyDev installation problems with Kepler and Mac OS

I have Eclipse (Kepler) installed on OS X and updated recently to Maverick. Since then I didn't start Eclipse. Yesterday I did and it told me that there are update available. I installed them, with the result that Eclipse didn't remember to have a perspective for PyDev.
I uninstalled PyDev, reinstalled it and since then it doesn't even appear in the preferences. I can uninstall it again, meaning Eclipse knows it is there, but there is simply no way to configure it.
Today I trashed the whole Eclipse, downloaded a fresh one and installed PyDev via the update site... Same story!
Has anybody the same problem on OS X?
Cheers, Tom
I've seen this on Windows 7, after a recent update to Eclipse Kepler and PyDev 3.0.x. The PyDev site states that the latest PyDev requires Java 7. If you don't have Java 7, use PyDev 2. (http://pydev.org/, under the "Release 3.0" title"). I'm using Java 6 to launch Eclipse.
I would check the versions of Java and PyDev you're running.
Not enough rep to comment on Gerry Kuhn's answer so I'll make a new one.
You can install java7 but retain your current version and not affect your current set up by specifying which JVM Eclipse should use using the command line -vm option.
All is explained here
Same problem on my Mac here with
Eclipse Version: Kepler Service Release 1
PyDev 3.0.0.201311051910 org.python.pydev.feature.feature.group
solved by using 2.x version
just download zip here and extracted folder in the dropin directory and restart is ok now
Thanks
I solved this problem by changing the eclipse.ini file.
I changed from this value
-vmargs
-Dosgi.requiredJavaVersion=1.6
to this value.
-vmargs
-Dosgi.requiredJavaVersion=1.7
But of course you must have jdk 7 installed previously.

Eclipse upgrade killed PyDev

I just upgraded my version of Eclipse on Ubuntu, and now whenever I open a Python file it opens in an external window, and the existing Python files I have open in Eclipse say "Could not open the editor: No editor descriptor for id org.python.pydev.editor.PythonEditor".
I tried uninstalling and reinstalling both Eclipse and the PyDev plugin, and it didn't fix the problem.
From my experience (~8 years) with eclipse don't do in place updates. Always install a fresh version with a new workspace. And re-checkout projects from SCM.
Check first whether all required plugins still work before switching to the new environment.
Make sure your Java version is correct (what your version of PyDev is expecting).
After I updated PyDev (5 min ago) I had the exact same error message displayed in the tabs where I once had python source files opened (No editor descriptor for id).
I updated my Java version from 1.7 to 1.8 with:
sudo apt-add-repository ppa:webupd8team/java
sudo apt-get update
sudo apt-get install oracle-java8-installer
Then to check your version, run:
java -version
You should see something like:
java version "1.8.0_91"
Java(TM) SE Runtime Environment (build 1.8.0_91-b14)
Java HotSpot(TM) Server VM (build 25.91-b14, mixed mode)
Re-opened eclipse, and the PyDev plugin is working. Yay!
Actually, when you install Eclipse new version then new plugins are installed which lead to change in ubuntu libraries and installing again will not take effect until you install new plugin which is supported
I had same issue, when I updgradet PyDev with newest version 3.*. It needs java 1.7, but I have only java 1.6, so it does not work at all. I uninstalled it and set eclipse to old updating point, but nothing helped. Advise is to use PyDev versio 2.82. You can not find it from update repositories.
Only way is to download old version 2.8.2 from PyDev site, unzip that zip file to eclipse's drop in directory, in linux it is /usr/lib/eclipse/dropins. After unzipping you should see there features- and plugins-directories. And after some starting of eclipse, I could see PyDev again. At first restart of eclipse I could not see PyDev and tried "Check updates" and "Install new software" settind url to /usr/lib/eclipse/dropins but they did not see any software there. But trying to restart few times, old PyDevc 2.8.2 was in eclipse again. Huh.
I disabled PyDev from eclipses "check uopdates" so I don't make that error again, this machine will not get java 1.7 (Ubuntu 10.04 LTS).
I now ran into exactly the same problem when updating to PyDev 5.0 and its definitely an issue that the user is not warned that the program might break on update. However, the simplest solution is to install the new required Java and JRE version, for PyDev 5.0 that's Java 8 and OpenJDK 1.8 (on Linux), and tell Eclipse to actually use the new JRE in the eclipse.ini file, by pointing it to the right path. See https://wiki.eclipse.org/Eclipse.ini#Specifying_the_JVM on how to achieve this.