Your project contains error(s), please fix it before running it

Question

I am developing a simple Android application. But when I run Eclipse, it shows the following error:

Your project contains error(s), please fix it befo

Answer 1

I had the same error, when I copied a project to another computer.

I then checked all properties of the project on both machines, and the only thing that was different was the order of items in Java Build Path - tab Order and Export.

I moved the items Android X.X.X and Android Dependencies above the other 2 in the list (in my case, src and gen folders) and voila, it worked again!

I'm not really sure if the different order was actually the problem, but at least changing it (and saving the properties again) seemed to help...