I had issues with xlam addins after a recend Windows 10 upate. Not sure if it is related.
The error was flagged to be Visual basic related and excel couldn't open the addin.
It seemed to be a security restriction but I wasn't apple to pin point a fix.
this is a question for your VAR.
its not an API question.
to find a resolution, one thing you can do is Download Windbg64
Attach it to Solidworks.
Watch for errors. if your lucky it will tell you the problem.
chances are that the DLL that Solidworks inspection was using has changed. they are using the installed version of excel and the interop library associated with that install. they didn't package or embed interop types in their code.
this is just my assumption.