To get this to work, I just had to run caspol.exe on each machine to make their machines trust that certain location, for example:
However in upgrading the add-ins to Revit 2012, this method did not work. The add-ins simply would not load, and in the journal file I was seeing this error:
This was when my assemblies were compiled in .NET 4 and the same error occurred after I recompiled them in .NET 3.5. I had a feeling that it might have something to do with the changes in security that were introduced with .NET 4, but the fact that it happened to .NET 3.5 dll’s as well was odd.
Turns out there’s a fix for it, which is a little bit of a pain, your user needs to update their revit.exe.config file in the Revit program directory (C:\Program Files\Autodesk\Revit Structure 2012\Program) and make the following change:
look for the <runtime> tag, and just after it’s opening, put:
The add-ins should then run correctly. This is however a bit of a pain, I’ll have to incorporate this into an installation tool. I’d love to hear of a better solution to this problem if anyone knows of one, however for now, this will work around it.
Thanks to this post for helping to point me in the right direction.