Her is my scenario
The main app (host) is installed on a PC.
The installation installs an assembly xyz in the GAC.
The main app is started. Since it has references to xyz an instance XYZ of xyz is created.
Now the main app loads several AddIns of similar kind that also have references to xyz.
How can I force all the AddIns to reference the XYZ instance of the main app?
Why do I want this?
XYZ holds some application wide shared variables that should always have the same value for the host and all AddIns.
Or is there a better approach than using one instance?