Recently upgraded to Eclipse 2020-12 (4.18.0) and Groovy hasn't worked since.
Upgraded Groovy with no improvement.
Now running (expanding all the "What's installed" tree)
- Eclipse Groovy Development Tools org.codehaus.groovy.eclipse.feature.feature.group
- Groovy Compiler 2.5 org.codehaus.groovy25.feature.feature.group
- Groovy-Eclipse Compilerless feature org.codehaus.groovy.compilerless.feature.feature.group
- Groovy-Eclipse Headless feature org.codehaus.groovy.headless.feature.feature.group
- Eclipse JDT Core patch for Groovy org.codehaus.groovy.jdt.patch.feature.group
- Groovy Compiler 3.0 org.codehaus.groovy30.feature.feature.group
All with version 4.0.0.v202012311505-e2009-RELEASE. However, the entry for "Eclipse JDT Core patch for Groovy" has a red '+' overlaid on its plugin icon.
Referring to the Eclipse log,
java.lang.NoClassDefFoundError: org/codehaus/jdt/groovy/integration/LanguageSupport
is being reported constantly. I'm assuming the patched JDT Core is not installed correctly but not sure what to do next.