I have a VB.NET Windows Forms (don’t laugh!!!) ClickOnce installation that includes a third party VB6 DLL. The project installs without any issues, but when I reach the code that calls for that VB6 DLL, I get an error saying that the .DLL isn’t registered. The DLL is included in the SomeApp.exe.manifest file. However, it’s not in the SomeApp.manifest file. Does it need to be in both? Or did I mess up somewhere else? I do notice the 3rd party VB6 DLL isn’t signed, if that matters at all. I’ve mainly be going off an older MSDN Magazine article, but referencing the latest MSDN documentation.
http://msdn.microsoft.com/en-us/magazine/cc188708.aspx
http://msdn.microsoft.com/en-us/library/ms165432.aspx
Turns out the 3rd party DLL we are trying to add is an Excel add-in.
http://msdn.microsoft.com/en-us/library/ms165432(v=vs.90).aspx
In that article, MSFT states that “Not every component is a suitable candidate for registration-free COM. A component is not a suitable if any of the following are true:The component is intended for use as an add-in or a snap-in, for example an Office add-in or a control in a Web browser. Such components typically require some kind of registration scheme defined by the hosting environment that is beyond the scope of the manifest itself.”
While we don’t use the file along with Excel, I’m thinking that might be why it doesn’t get recognized at runtime. We’ve asked the vendor for a compatible reg-free COM file. In the meantime we’ll need to add that file to the prerequisites script. Not as encapsulated as I’d like.
Before I select this as an answer, I’d like to see if anyone else agrees that could be the issue.