Unable to delete modules after updating
From Joomla! Documentation
Revision as of 12:20, 21 November 2013 by Sovainfo
What is the cause
When a site is upgraded to 3.2, users are unable to delete modules and are shown a generic "An error has occurred" message. This also applies to trying to empty trash in the module manager.
How to fix
In order to delete modules, you will first need to open the module(s) you want to delete for editing and save them. After this, you will be able to delete the module(s).