Error building Player: 3 errors , to try build & run

When I try a build & run with my android device connected and recognized, the compilation does not end and the console displays the message: “Error building player: 3 errors”, and no other messages to help identify what the problem is. How to solve?

Did you ever figure this out? I am getting 22 errors with nothing to go on. I am able to build and then install but cant build to device.