Edhy your Link was Right On. I only used the following part of it but it Registered the Dll's.
"C:\Program Files (x86)\Microsoft SDKs\Windows\v10.0A\bin\NETFX 4.6.1 Tools\gacutil.exe" /if "C:\Program Files (x86)\Common Files\MicroFour\StrataFrame\MicroFour StrataFrame AddIns.dll" /f
And the same for the other dll.
I guess there is a new(er) version of gacutil that must be used or something. Not sure of course but it worked.