Weird compile error PLEASE HELP

I am working on a project at multiple locations. On all locations but one everything works fine. On the last location I can't run or compile because of this error. "Compile error: Can't find project or library" It says this at the first variable it comes across.

Any idea what this could be?
I turned off "Require variable declaration"

It probably means that those computers are missing a certain referance your project is using.