Requires Unloadable Type

[Skeptical]

Unfortunately, I can't share code but here is my situation. I have 2 VB.NET DLLs. The first DLL references the second. Then in TestStand 2010 SP1 I have an Action step that calls a method in the first DLL that returns a type from the second DLL. When I try to setup the method call in the step settings it shows an error "Requires Unloadable Type". If I change the return type to something like Integer I no longer get that error. Oddly, if I setup an action step in TestStand calling a method in the second DLL I get no error. I am baffled by this and can't see what the problem is. Any ideas on what to look for to solve this?

[dug9000 · Accepted solution]

If you put both dlls in the same directory the problem will likely go away.

The problem you are having is that the .NET framework can't find the second dll when you specify the first dll unless you do one of the following:

1) put it in the same directory as the first dll.

2) put it in the GAC

3) put it in the directory of your exe (the TestStand bin directory in the case of the sequence editor).

I recommend doing 1).

Hope this helps,

-Doug

[Skeptical]

Just like you said, the 2nd DLL wasn't being found because it or a dependency wasn't in a folder that was being accessed by the search directories. We made sure all DLLs were in the same folder and called them out from there in our sequence file and that resolved the problem.

Thanks for the suggestions.