I switched from log4j to logback.

I initially used logback.xml . I wanted to get rid of xml, hence switched over to logback.groovy.

I used to get :

Failed to instantiate [ch.qos.logback.classic.LoggerContext]
Reported exception: java.lang.VerifyError: (class:groovy/runtime/metaclass/java/lang/StringMetaClass, method: super$2$invokeMethod signature: (Ljava/lang/Class;Ljava/lang/Object;Ljava/lang/String;[Ljava/lang/Object;ZZ)Ljava/lang/Object Illegal use of nonvirtual function call

I googled around to resolve the issue, but it was not helpful. Finally i reported the issue to logback-users group. The issue was resolved in a jiffy. Now the program is working perfectly.

The issue was another jar was using a lower version of groovy (1.1) while logback was on 1.7.

A FAQ about the logback groovy failure in case of lower version of groovy present in the class path would be much helpful to debug.

Also a list of popular jars that use groovy would also help to fix the problem at earliest.

Kindly have one such.

Regards
Rathnadhar.K.V