ClassCastException during indexing

We're getting the following stack dump during indexing in our test Jira instance (v5.2, build 812). I've looked around and found similar issues/fixes, but they don't seem to apply in our case.

2013-09-10 16:58:32,874 JiraTaskExectionThread-9 ERROR mhammel 1017x3229x1 1h6t7sx 10.125.1.66 /secure/admin/jira/IndexReIndex.jspa [jira.util.index.CompositeIndexLifecycleManager] Reindex All FAILED. Indexer: DefaultIndexManager: paths: [/var/atlassian/application-data/jira/caches/indexes/comments, /var/atlassian/application-data/jira/caches/indexes/issues, /var/atlassian/application-data/jira/caches/indexes/changes]

java.lang.RuntimeException: java.util.concurrent.ExecutionException: java.lang.ClassCastException

at com.atlassian.jira.index.FutureResult.await(FutureResult.java:35)

at com.atlassian.jira.index.CompositeResultBuilder$CompositeResult.await(CompositeResultBuilder.java:82)

at com.atlassian.jira.issue.index.DefaultIndexManager.doIndexIssuesInBatchMode(DefaultIndexManager.java:855)

at com.atlassian.jira.issue.index.DefaultIndexManager.doStopTheWorldReindex(DefaultIndexManager.java:825)

at com.atlassian.jira.issue.index.DefaultIndexManager.reIndexAll(DefaultIndexManager.java:335)

at com.atlassian.jira.issue.index.DefaultIndexManager.reIndexAll(DefaultIndexManager.java:301)

at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)

at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)

at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)

at java.lang.reflect.Method.invoke(Unknown Source)

at com.atlassian.util.profiling.object.ObjectProfiler.profiledInvoke(ObjectProfiler.java:81)

at com.atlassian.jira.config.component.SwitchingInvocationHandler.invoke(SwitchingInvocationHandler.java:28)

at $Proxy117.reIndexAll(Unknown Source)

at com.atlassian.jira.util.index.CompositeIndexLifecycleManager.reIndexAll(CompositeIndexLifecycleManager.java:54)

at com.atlassian.jira.web.action.admin.index.ReIndexAsyncIndexerCommand.doReindex(ReIndexAsyncIndexerCommand.java:28)

at com.atlassian.jira.web.action.admin.index.AbstractAsyncIndexerCommand.call(AbstractAsyncIndexerCommand.java:54)

at com.atlassian.jira.web.action.admin.index.ReIndexAsyncIndexerCommand.call(ReIndexAsyncIndexerCommand.java:16)

at com.atlassian.jira.web.action.admin.index.AbstractAsyncIndexerCommand.call(AbstractAsyncIndexerCommand.java:23)

at com.atlassian.jira.task.TaskManagerImpl$TaskCallableDecorator.call(TaskManagerImpl.java:366)

at java.util.concurrent.FutureTask$Sync.innerRun(Unknown Source)

at java.util.concurrent.FutureTask.run(Unknown Source)

at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source)

at java.util.concurrent.FutureTask$Sync.innerRun(Unknown Source)

at java.util.concurrent.FutureTask.run(Unknown Source)

at com.atlassian.multitenant.impl.DefaultMultiTenantManager.runForTenant(DefaultMultiTenantManager.java:61)

at com.atlassian.multitenant.juc.MultiTenantExecutors$WrappedRunnable.run(MultiTenantExecutors.java:160)

at com.atlassian.jira.task.ForkedThreadExecutor$ForkedRunnableDecorator.run(ForkedThreadExecutor.java:249)

at java.lang.Thread.run(Unknown Source)

Caused by: java.util.concurrent.ExecutionException: java.lang.ClassCastException

at java.util.concurrent.FutureTask$Sync.innerGet(Unknown Source)

at java.util.concurrent.FutureTask.get(Unknown Source)

at com.atlassian.jira.index.FutureResult.await(FutureResult.java:31)

... 27 more

Caused by: java.lang.ClassCastException

2013-09-10 16:58:32,875 JiraTaskExectionThread-9 INFO mhammel 1017x3229x1 1h6t7sx 10.125.1.66 /secure/admin/jira/IndexReIndex.jspa [action.admin.index.IndexAdminImpl] Re-indexing finished