I have a couple of fortran dll's (Intel® Parallel Studio XE 2016 Update 1 Composer Edition for Fortran Windows) that get loaded into a c++ program. After they're done I'd like to unload the dll's. One of them unloads fine. The other won't. Even if I put the whole operation on a separate thread, doing the FreeLibrary and closing the thread, still leaves the one dll (and the dll's that it loads) attached to the process.
For the dll in question I tried doing a FreeLibrary right after the LoadLibrary, and it still fails.
So, what's making the dll so "sticky" and what can I try to fix it?