UEAsLibrary mouse input not working as app is never active

The steps that are required:

  1. build your project using what described in the docs.
  2. export and cook the content.
  3. Copy your project dll where needed
  4. Copy your cooked content (both YourProject and Engine directory) two levels up in the directory tree from where you put your exe/dll
  5. Everything should work now.

I think you are missing your project content (step 4).