Exception when creating a new project

We are currently testing You Track and we love al the functionalities.

Except we found a problem.

We are using the free licence and have currently  5 projects in our test phase.

We want to add another one and we always get this error message.

We just update to 3.1 but in version 3.04 the problem also occured.

How can i fix this problem?

link to the execption details

http://youtrack.jetbrains.net/issue/JT-12640?projectKey=JT