After update to J 3.3.1 I can no longer access Categories or Documents from the Administration Page. I still can list the items but it fails to see the Details. Objects are still accessible in the front-end.
What version of the extension you are using ? Could you please upgrade to version 1.5.7 of EDocman as old version of EDocman is not compatible with Joomla 3.3.1 due to some changes in Joomla core API (from version 3.3.0)
