>>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.

I'd just set COM visible to false - as long as you remember that if you change the public interface you would need to (on a one off basis) set it back to true and build as Admin,,,,