STS Upgrate leads to MatchLocator problems

Question

I recently let STS update itself from 3.1 to 3.5 and now I'm getting errors regarding the MatchLocator class. I'm not sure what MatchLocator is, but it appears to be a core Eclipse service.

When I open STS I get 'Initializing Java Tooling' has encountered a problem.

An internal error occurred during: "Initializing Java Tooling". org/eclipse/jdt/internal/core/search/matching/MatchLocator

After it's open I get an error marker for each applicationContext.xml in each project that says

java.lang.NoClassDefFoundError: org/eclipse/jdt/internal/core/search/matching/MatchLocator

No lines are marked, just that it's a "Spring Beans Problem"

When I close STS I get Problmes occurred while trying to save the state of the workbench with details:

An internal error occurred during: "Initializing Java Tooling". org/eclipse/jdt/internal/core/search/matching/MatchLocator

I've tried downloading a fresh copy of STS 3.5 to a separate directory and each of my workspaces still have this error so I suspect the problem is in the .metadata directory. A couple other Stack Overflow posts have recommended deleting the workspace .metadata or .metadata\.plugins directories and letting Eclipse rebuild them for that workspace but that didn't fix it either.

I'm running on a Mac with these plugins: m2e Maven Integration and associated plugins, Scala IDE, STS and StartExplorer.

Is there a way to restore the missing MatchLocator files?

Answer 1

Fixed this by removing this file in each workspace:

[workspace]/.metadata/.plugins/org.eclipse.e4.workbench/workbench.xmi

Opening STS from the command line (on mac: ./STS.app/Contents/MacOS/STS -clean) and viewing stack traces on startup led me to this answer: https://stackoverflow.com/a/13884461/1637003

Now all the random ways this bug was manifesting itself have gone away: JUnit tests not running, cmd+clicking to open declarations not working, various MatchLocator errors on startup and shut down.