Preview and Build

I am in deep trouble:

When playing my game in Unity itself, the game runs fine as it should and is expected.
However, when trying to export it to a standalone, I get this list of errors:
Error CS0436: The type ‘’ conflicts with imported type ‘’. Ignoring imported type.

I get this error for about 10 scripts.

This morning the build worked fine. The only thing I changed was the player model (adding more animations).
Does anyone know how I can make this shit alright again?
My project deadline is tomorrow :frowning:

Just a thought… is it possible that the built standalone has ended up in the assets folder by accident? If so, remove it (ie, delete it within the Unity editor) and things should go back to normal.