Permissions to load assembly at runtime in ASP.NET MVC

I'm currently working on a function for my website that should work like this:

• User upload an dll
• I load the dll inside another app domain (with Assembly.LoadFrom) to inspect it with reflection
• Unload the app domain and delete the .dll file

This works perfectly fine when I do it locally but when I upload it to my server I get:

Failed to generate files: Could not load file or assembly '/the/path' or one 
of its dependencies. Operation is not supported. (Exception from HRESULT: 0x80131515)

So the "Operation is not supported" make me a bit curious. Is it some kind of permission that I need to set the server? Or is it something I can fix through my config? Or is it simply that my server actually don't support it at all?

The only information I can see on my Windows/IIS server is that it use .NET version 4.

Set project Property Local copy = true ,if you are loading using reflection then provide deployment Item at Class level it will work.