Eclipse BIRT: Debugger throws "Unhandled event loop exception" - eclipse

Question

I am trying to use Eclipse debugger to debug BIRT report but when I click Debug or run my report from debug perspective I get Unhandled event loop exception.
I get this error with the latest version of the designer, with the older version I am able to use the debugger. Below is the stack trace. Any pointer to troubleshoot this will be helpful.
org.eclipse.swt.SWTException: Failed to execute runnable (java.lang.NullPointerException)
at org.eclipse.swt.SWT.error(SWT.java:4491)
at org.eclipse.swt.SWT.error(SWT.java:4406)
at org.eclipse.swt.widgets.Synchronizer.runAsyncMessages(Synchronizer.java:138)
at org.eclipse.swt.widgets.Display.runAsyncMessages(Display.java:4155)
at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3772)
at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine$4.run(PartRenderingEngine.java:1127)
at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:337)
at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.run(PartRenderingEngine.java:1018)
at org.eclipse.e4.ui.internal.workbench.E4Workbench.createAndRunUI(E4Workbench.java:156)
at org.eclipse.ui.internal.Workbench$5.run(Workbench.java:694)
at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:337)
at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:606)
at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:150)
at org.eclipse.ui.internal.ide.application.IDEApplication.start(IDEApplication.java:139)
at org.eclipse.equinox.internal.app.EclipseAppHandle.run(EclipseAppHandle.java:196)
at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.runApplication(EclipseAppLauncher.java:134)
at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.start(EclipseAppLauncher.java:104)
at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:380)
at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:235)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:669)
at org.eclipse.equinox.launcher.Main.basicRun(Main.java:608)
at org.eclipse.equinox.launcher.Main.run(Main.java:1515)
Caused by: java.lang.NullPointerException
at org.eclipse.birt.report.engine.api.impl.GetParameterDefinitionTask.getDefaultValue(GetParameterDefinitionTask.java:338)
at org.eclipse.birt.report.designer.ui.parameters.ScalarParameter.getDefaultValues(ScalarParameter.java:202)
at org.eclipse.birt.report.designer.ui.dialogs.AbstractParameterControlHelper.getPreSetValue(InputParameterDialog.java:528)
at org.eclipse.birt.report.designer.ui.dialogs.AbstractParameterControlHelper.prepareControlDefaultValue(InputParameterDialog.java:515)
at org.eclipse.birt.report.designer.ui.dialogs.AbstractParameterControlHelper.init(InputParameterDialog.java:503)
at org.eclipse.birt.report.designer.ui.dialogs.AbstractParameterControlHelper.createControl(InputParameterDialog.java:404)
at org.eclipse.birt.report.designer.ui.dialogs.InputParameterDialog.createParamSection(InputParameterDialog.java:271)
at org.eclipse.birt.report.designer.ui.dialogs.InputParameterDialog.createParametersSection(InputParameterDialog.java:209)
at org.eclipse.birt.report.designer.ui.dialogs.InputParameterDialog.createParameters(InputParameterDialog.java:194)
at org.eclipse.birt.report.designer.ui.dialogs.InputParameterDialog.createDialogArea(InputParameterDialog.java:175)
at org.eclipse.jface.dialogs.Dialog.createContents(Dialog.java:768)
at org.eclipse.jface.window.Window.create(Window.java:430)
at org.eclipse.jface.dialogs.Dialog.create(Dialog.java:1096)
at org.eclipse.birt.report.designer.ui.dialogs.BaseDialog.open(BaseDialog.java:107)
at org.eclipse.birt.report.debug.internal.ui.script.launcher.ReportLaunchHelper.getParameterValues(ReportLaunchHelper.java:326)
at org.eclipse.birt.report.debug.internal.ui.script.launcher.ReportLaunchHelper.access$2(ReportLaunchHelper.java:319)
at org.eclipse.birt.report.debug.internal.ui.script.launcher.ReportLaunchHelper$1.run(ReportLaunchHelper.java:417)
at org.eclipse.ui.internal.UILockListener.doPendingWork(UILockListener.java:162)
at org.eclipse.ui.internal.UISynchronizer$3.run(UISynchronizer.java:154)
at org.eclipse.swt.widgets.RunnableLock.run(RunnableLock.java:35)
at org.eclipse.swt.widgets.Synchronizer.runAsyncMessages(Synchronizer.java:135)
... 23 more

Answer 1

Do you have your reports set up as an Eclipse-project, i.e. do you have a .project file? If so, try to comment/delete all <nature>-tags or lines from that file. Than restart BIRT and reopen the project.