I recently grabbed the VB.NET Task Add-In sample off the forum, compiled it up with VS2012 Express and was testing it on our EPDM 2014 SP2 installation.  I had added and removed the Add-In several times, while also creating and deleting a new Task using the Add-In.  All without editing the sample code.

Now, when I select 'Add-ins->New Add-in ...', I just get the dialog (I attached below)... 'Class Not Registered'.  Exact same thing happens when I attempt to add a new task.  I tried to see if I could uninstall my Add-In.dll via regsvr32 & regasm, but to no avail.  Then, I attempted to extract directly out of the Registry via RegEdit, but again no success.  Finally, I uninstalled and re-installed the PDM client tools and have the exact same behavior with a fresh install of the client tools.

Does anyone have any thoughts?  I'm not exactly sure how Task Add-Ins are managed or distributed by the PDM Server... if at all.