UPDATED
Check your index.gsp file and remove the line showing the Groovy version.
org.codehaus.groovy.runtime.InvokerHelper.getVersion has changed to GroovySystem.getVersion in newer Groovy builds bundled in Grails.
Initially I would have said that you upgraded projects from previous Grails versions.
- Install a new version of Grails
- Update the application.properties file
- Run grails upgrade
- Create a new blank project and compare the BuildConfig.groovy to see if a dependency needs upgrading.
I think that the index.gsp modification will do it. If not, please add details about the actions that you're taking and when the error occurs(stacktrace will also be needed).