Do you have Patch 3 or later installed on your website? I think this issue corresponds to bug #91052 that was re-fixed in Patch 3.
Also there is a couple of dirty workarounds, but they are far from ideal in case of add-ons. See details here.
Yeah thanks that seems to have been the issue.
Trying to create an example add-on for our development process and I am getting the following error when I try to add a block from the add-on to a content area on a page. The self-optimizing block from EPiServer also shows the same error so I'm assuming it is likely a configuration error but can't seem to find anything sepcific that would relate to this.
The controller for path '/EPiServer/CMS/en/Help/Examples/Optimization-Block,,146_525/' was not found or does not implement IController.
We have added a custom viewengine to reorganize the structure of the Views could this be causing the issue? If it is how do we overide the view engine and support addons?