Opening issue is very slow and workflow-actions aren't available

I tried to migrate from version 2.5.1 to 2.5.2 and kept the database-instance the same.

In version 2.5.1 opening an issue is an action where waiting is maybe 1 sec.
Since version 2.5.2 opening an issue is waiting more then 15 secs.

It's also impossible to do workflow-actions (closing, in progress, resolving, reopening,...)

The JIRA/Tomcat Windows says that there is a time-out with your workflow-engine findin a host.

When i copy following two files back from version 2.5.2 to version 2.5.1 (server.xml and entityengine.xml) version 2.5.1 works just fine.