Unable to create issue

I was evaluating version 2.5.1 for our company CIPAL in Belgium when version 2.5.2 was released.

Because for us it was important to know how easy it was to upgrade JIRA with another language (we are translating the frontend into Dutch) we tried to upgrade from 2.5.1 to 2.5.2.

At first it seemed to be OK until we wanted to create an issue. There was a message indicating there was a problem with the workflow. So we can't create issues anymore.

At first I though I made a fault so i tried a clean install from your version 2.5.2 on a new MySQL-database. After entering a project and versions the fault-message didn't dissapear.

In attach you can find some screenshots.