I seem to have persistent problem in our test and prod environment. We have custom add-on created by customer and now they are unable to install new version or remove existing one because of access denied error from the add-on dll in modulesbin. Why? What is blocking the file or what special access rights should I set to files? I've tried adding full control to user running the app_pool and also for IUSR in a desperate moment.
Damn and now I found the reason: I had added the name of custom add-on to compilation/assemblies to tackle another problem we had with the add-on and that one line in web.config caused access denied. application pool process blocking dlls in assemblies or what?
Now I feel stupid - again.