Question

I get an error when I try to deploy a war-file created by Grails.

I’m using the Spring security plugin and deploying om Tomcat 7.

After reading about similar problems I think it has something to do with the plugin not being packed in to the war but I’m not entirely sure.

Here is what the catalina.out-file displayed:

log4j:ERROR Error initializing log4j: grails/plugins/springsecurity/SecurityConfigType : Unsupported major.minor version 51.0 (unable to load class grails.plugins.springsecurity.SecurityConfigType)
java.lang.UnsupportedClassVersionError: grails/plugins/springsecurity/SecurityConfigType : Unsupported major.minor version 51.0 (unable to load class grails.plugins.springsecurity.SecurityConfigType)
        at java.lang.Class.forName0(Native Method)
        at java.lang.Class.forName(Class.java:186)
        at Config.class$(Config.groovy)
        at Config.$get$$class$grails$plugins$springsecurity$SecurityConfigType(Config.groovy)
        at Config.run(Config.groovy:116)
        at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:334)
        at java.util.concurrent.FutureTask.run(FutureTask.java:166)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603)
        at java.lang.Thread.run(Thread.java:636)
08-Nov-2011 17:56:12 org.apache.catalina.core.StandardContext startInternal
SEVERE: Error listenerStart

Answer 1

Unsupported major.minor version 51.0 tells you that you are compiling and running with different java versions (like JRE 7 and JDK 6).

Check the JDK versions on your computer.