After upgrading a Grails application from 2.2.0 to 2.2.1 I keep getting the following error when attempting to debug a Grails application from GGTS via Debug as... -> Grails
I had the same problem, I was picking up groovy-all 2.0.7 from GGTS and 2.0.8 from my grails project. To resolve the problem I removed the "Groovy Dependencies" library from the eclipse project.
Right click on project -> Properties -> Java Build Path -> Libraries (tab) -> Groovy Dependencies -> Remove