Symptoms

When attempting to configure JIRA with Subversion 1.6, the following error is recorded in your logs:

svn: Unable to open an ra_local session to URL svn: Unable to open repository 'file:///var/svn/project' svn: Expected FS format between '1' and '3'; found format '4'
Error occurred while updating the repository. Please refer to the log for more details.

Cause

The svn kit packaged with the JIRA Subversion plugin is not compatible with subversion 1.6.

Resolution

Download the latest jar from the svn kit page and replace the old jar delivered with the plugin with the updated one you downloaded. After this you must restart of JIRA for the changes to take effect.