I've been trying to use GREclipse with no success on an Indigo installation. I've tried with today's (2011/09/14) development snapshot as well as with lastest release version. Also I've tried with 1.7 and 1.8 compilers, always with the same errors.
Anytime I try to create a new class, I get this error:
"Creation of element failed.
org.eclipse.jdt.internal.core.CompilationUnit cannot be cast to org.codehaus.jdt.groovy.model.GroovyCompilationUnit".
I've attached the full exception on eclipse log (ex1.txt)
Anyway, the class is created. But anytime I double click on it, I get the following response (similar to bug https://jira.codehaus.org/browse/GRECLIPSE-1177, but not the same)
"An error has occurred. See error log for more details.
When I check the log, I see the exception I've attached on ex2.txt.
Hope this helps!