Flutter doctor hangs on start, no output - flutter

Question

I'm trying to install Flutter on my Windows 8 computer. I unzipped files to C:/flutter and added the bin folder to the path variable. However I am stuck on the step where I have to run flutter doctor in flutter_console. The Flutter doctor hangs and only shows the blinking cursor and no output. More interestingly any other flutter command will freeze the exact same way.
I have already tried
Running flutter console as admin
Reinstalling flutter
Installing the dev version
Use the VS code plugin to run flutter doctor
But they all led to the same result

Answer 1

So the solution of this issue is:
delete folder in your flutter SDK path flutter/bin/cache (detail info here)
run flutter doctor -v again will trigger downloading Dart SDK
PS: if your network is slow because of in china, check bellow:
Do things bellow in terminal maybe speed up your the download speed (for me it's speed up 3x) for changing channel:
export FLUTTER_STORAGE_BASE_URL=https://storage.flutter-io.cn (detail info here)
flutter channel stable (one example of change flutter channel)
flutter doctor -v (trigger downloading SDK)

Answer 2

Albeith in win10, these steps solved the issue for me (do not know if all are necessary)
restart win
run cmd as administrator
flutter doctor
According to this git issue, this is mostly caused by installing flutter in a directory for which you do not own the priviledges. For example, the Program Files folder: to solve then, you can try to move the installation folder

Answer 3

Problem
I had the same problem while trying to reinstall flutter using the recommended windows install guide found here https://docs.flutter.dev/get-started/install/windows
(flutter_windows_3.3.9-stable).
All flutter commands would hang and only show the flashing cursor. It did not matter if I was in the flutter console, PowerShell, VS Code terminal or Admin Command prompt.
This made running flutter doctor impossible, and thus I couldn't complete the flutter setup.
Environment
I am using a PC running Windows 10.
I am located in North America. (If you are in China, you may need to use a proxy server for the initial download).
Flutter was installed on a drive with ample free space in a non-restricted folder.
I have a stable internet connection.
I have git for windows installed and have set up my ssh keys. (you can download and install this form here https://git-scm.com/download/win).
I have my Windows Firewall and network protection on. (You may need to turn off third party firewalls or add a rule to them allowing flutter to make connections to the internet during the flutter setup).
Solution
This solution worked for me and should resolve most install problems related to installing flutter on a Windows environment.
Please upvote if it works for you.
Step 0 - Remove flutter from system:
If reinstalling flutter, do this step, otherwise move to step 1 if preforming a fresh installation.
Open file explorer and delete the folder titled flutter if already installed.
Type environment variables into the windows search bar and open Edit the system environment variables.
Click environment variables in the Advanced tab.
Double-click the word Path found under User variables for {YOUR USER NAME}.
Select any entries that end with \flutter or \flutter\bin and delete them.
Click the Ok button and then the Ok button to apply the changes.
Step 1 - Download Stable Flutter Version:
Go to the official flutter website https://docs.flutter.dev/development/tools/sdk/releases and download the most recent flutter version in the Stable channel (Windows).
Once downloaded, unzip the folder.
Place the flutter folder found inside the Zip file wherever you would like to store it on your computer. Flutter recommend putting it in C:\src\flutter. You can place it where've you like as long as It's not in a folder that requires elevated privileges to access, such as the C:\Program Files\ folder.
Note* I used Windows Explorer to unzip the file, however others report used 7-Zip file Manager for unzipping solved their problem.
Step 2 - Setup Environment Variables:
Type environment variables into the windows search bar and open Edit the system environment variables.
Click environment variables in the Advanced tab.
Double-click the word Path found under User variables for {YOUR USER_NAME}.
Click Browse... and navigate to where you placed the flutter folder. Then navigate to the bin file inside the flutter folder and click ok.
A new environment variable should have been added that looks like C:\src\flutter\bin.
You also need to make sure Git\bin\cmd, Git\bin\git.exe and, C:\Windows\System32\WindowsPowerShell\v1.0\ system environment paths are setup. These were post likely configured during your git for windows install.
Follow the "Update your path section" found here https://docs.flutter.dev/get-started/install/windows if this doesn't work for you.
Note* If Path doesn't exist, click new... and set variable name to Path and Variable value to the file path of your bin folder found in the flutter folder you just unzipped.
Step 3 - Reboot your computer in Safe Mode with Networking:
Press the Windows key + I on the keyboard to open Settings, or type settings in the windows search bar.
Click Update & Security and on the left pane select Recovery.
Under Advanced Startup, click Restart Now.
After the computer restarts, on the Choose an Option screen, select Troubleshoot > Advanced Options > Startup Settings > Restart.
After the computer restarts, a list of options appears. Select 5 or F5 for Safe Mode with Networking or whatever key your computer says to boot into Safe Mode with Networking.
Step 4 - Launch Administrator Command Prompt:
After rebooting, type command prompt into the windows search bar.
Right-click the application icon and click Run as administartor.
Run the following commands, flutter pub cache repair then flutter doctor -v. This might take quite some time if you have poor internet, as it will re-downloads every package in the cache.
If flutter doctor reports any red or yellow warnings with your environment, you need to resolve these first before continuing. These are quite common, and a Google search of the error or warning should solve your problem.
Note* if the command flutter is unrecognized, this means you didn't set up your environment path variables in step 2 correctly.
Step 5 - Reboot and run your project
Now that flutter doctor has run in safe mode, we can restart the computer and get out of safe mode.
Open your flutter project in Visual Studio Code.
Open a terminal window under terminal > new Terminal.
run the command, git config --global --add safe.directory C:/src/flutter make sure you use forward / and set the file path to wherever you saved your flutter folder. This can also be run from the administrator command prompt if you don't have VS Code or a flutter project.
Then run flutter doctor -v in the VS Code terminal to make sure everything is working.
Now we need to rebuild all of our packages and dependencies, run the following list of commands in order.
flutter clean
flutter pub cache repair
flutter pub get
flutter pub upgrade --major-versions
Troubleshooting
These are other solutions I noticed on stack overflow while trying to solve the problem for myself. These didn't work for my situation, but may help you solve yours.
Flutter doctor, running very slowly. Try deleting the cache folder found in, C:\src\flutter\bin\cache\ then running flutter doctor -v again. Flutter doctor hangs on start, no output
If you are in China. Download flutter through a mirror site.
Try installing a different type of unzip program (like 7-zip).
Make sure you are using the Stable flutter channel.
Make sure your path variables are set up correctly.
getting error "Waiting for another flutter command to release the startup lock" Use task manager to forcibly close any flutter or dart programs.
Can't delete old flutter folder, in use for some reason. Restart and immediately delete the folder.
Make sure flutter isn't installed in a folder that requires admin privileges to access, such as C:\Program Files\.
Make sure you have git for windows installed and have set up your ssh keys.
Add the Flutter and Dart extensions to VS Code.
Add the flutter and Dart plugins to Android Studio.

Answer 4

Delete the cache folder inside bin folder of the flutter sdk then run flutter doctor it should work now.