NullPointerException When Doing Restore

 Error 2013-11-04 17:53:20,760 [http-bio-8080-exec-1] ERROR errors.GrailsExceptionResolver  - NullPointerException occurred when processing request: [GET] /modeshape-version-testcase/version/testVersion
Stacktrace follows:
Message: null
    Line | Method
->>   46 | getPath        in org.modeshape.jcr.cache.PathCache
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 
   1127 | persistChanges in org.modeshape.jcr.cache.document.WritableSessionCache
    620 | save . . . . . in     ''
   1141 | save           in org.modeshape.jcr.JcrSession
    904 | restore . . .  in org.modeshape.jcr.JcrVersionManager
    712 | restore        in     ''
     59 | testVersion .  in modeshape.version.testcase.VersionService
      8 | testVersion    in modeshape.version.testcase.VersionController
    195 | doFilter . . . in grails.plugin.cache.web.filter.PageFragmentCachingFilter
     63 | doFilter       in grails.plugin.cache.web.filter.AbstractFilter
   1145 | runWorker . .  in java.util.concurrent.ThreadPoolExecutor
    615 | run            in java.util.concurrent.ThreadPoolExecutor$Worker
^    722 | run . . . . .  in java.lang.Thread