>The answer is in the error : Access to the registry key 'HKEY_CLASSES_ROOT\Siriusware.Middleware.ErrorState' is denied."
>
>Writing to the registry requires elevated rights. If this is a COM assembly you could turn off the registration (which IAC only needs to be done if the interface changes). If you do need to re-register than use regasm or, as a one off, set the COM interop flag and run as Admin.

I found the ComVisible(true) in the AssemblyInfo file. Should I turn this off in my local copy? Would this be enough or not?

For now I decided it's just a small nuisance to always remember to run VS as Admin for this project.