Eclipse/STS starts once - then fails to start again - Mac/Catalina 10.15.7

Question

After trying to install a CVS client into Eclipse/STS (ver 4.7.1) that I use no longer loads. I've re-installed Eclipse/STS a couple of times, but the startup issue persists...I get the exceptions listed below. On intermittent tries after deleting the .metadata/ folder from the workspace, it sometimes loads. But once I close it and try to re-open it never starts on that workspace again.

Things I've tried from other (older) stack-overflow posts :

• Reinstalling STS, a couple of time...the CVS client "should" no longer be an issue...It's not even installed on the re-installed version.
• Deleting the workspace.xmi file.

Nothing seems to work...And from the stacktrace below, I can't tell what the NullPointerException is referring to. I did verify there is a LegacyIDE.e4xmi file in the location indicated, and I have R/W permissions to it.

Here are the errors in the .log I see.

!SESSION 2020-09-29 13:03:57.621 -----------------------------------------------
eclipse.buildId=4.7.1.202007271558-RELEASE
java.version=1.8.0_261
java.vendor=Oracle Corporation
BootLoader constants: OS=macosx, ARCH=x86_64, WS=cocoa, NL=en_US
Framework arguments:  -product org.springframework.boot.ide.branding.sts4 -keyring /Users/n0002501/.eclipse_keyring
Command-line arguments:  -os macosx -ws cocoa -arch x86_64 -product org.springframework.boot.ide.branding.sts4 -keyring /Users/[myuser]/.eclipse_keyring

!ENTRY org.eclipse.e4.ui.workbench 4 0 2020-09-29 13:04:13.603
!MESSAGE Unable to load resource platform:/plugin/org.eclipse.platform/LegacyIDE.e4xmi
!STACK 0
java.lang.NullPointerException
    at org.eclipse.e4.ui.internal.workbench.ResourceHandler.getResource(ResourceHandler.java:287)
    at org.eclipse.e4.ui.internal.workbench.ResourceHandler.loadResource(ResourceHandler.java:263)
    at org.eclipse.e4.ui.internal.workbench.ResourceHandler.loadMostRecentModel(ResourceHandler.java:181)
    at org.eclipse.e4.ui.internal.workbench.swt.E4Application.loadApplicationModel(E4Application.java:384)
    at org.eclipse.e4.ui.internal.workbench.swt.E4Application.createE4Workbench(E4Application.java:260)
    at org.eclipse.ui.internal.Workbench.lambda$3(Workbench.java:579)
    at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:338)
    at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:557)
    at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:154)
    at org.eclipse.ui.internal.ide.application.IDEApplication.start(IDEApplication.java:150)
    at org.eclipse.equinox.internal.app.EclipseAppHandle.run(EclipseAppHandle.java:203)
    at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.runApplication(EclipseAppLauncher.java:137)
    at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.start(EclipseAppLauncher.java:107)
    at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:401)
    at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:255)
    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:657)
    at org.eclipse.equinox.launcher.Main.basicRun(Main.java:594)
    at org.eclipse.equinox.launcher.Main.run(Main.java:1447)

!ENTRY org.eclipse.osgi 4 0 2020-09-29 13:04:13.630
!MESSAGE Application error
!STACK 1
java.lang.NullPointerException
    at org.eclipse.e4.ui.internal.workbench.ResourceHandler.loadMostRecentModel(ResourceHandler.java:182)
    at org.eclipse.e4.ui.internal.workbench.swt.E4Application.loadApplicationModel(E4Application.java:384)
    at org.eclipse.e4.ui.internal.workbench.swt.E4Application.createE4Workbench(E4Application.java:260)
    at org.eclipse.ui.internal.Workbench.lambda$3(Workbench.java:579)
    at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:338)
    at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:557)
    at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:154)
    at org.eclipse.ui.internal.ide.application.IDEApplication.start(IDEApplication.java:150)
    at org.eclipse.equinox.internal.app.EclipseAppHandle.run(EclipseAppHandle.java:203)
    at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.runApplication(EclipseAppLauncher.java:137)
    at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.start(EclipseAppLauncher.java:107)
    at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:401)
    at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:255)
    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:657)
    at org.eclipse.equinox.launcher.Main.basicRun(Main.java:594)
    at org.eclipse.equinox.launcher.Main.run(Main.java:1447)

Answer 1

Figures, as soon as I post the question, I found a solution here :

STS launch issue on Mac

Posted 8 years ago...but it works now. For anyone experiencing this, that org.eclipse.osgi folder is buried in the Mac SpringToolSuite.app contents...which is what the NullPointerException in the stacktrace lists.

I can only surmise that installation of the CVS Client left that in a corrupt state, but I would've thought a Re-install would have gotten rid of it.