Error building Player: CommandInvokationFailure: Failed to re-package resources. See the Console for details

Error building Player: CommandInvokationFailure: Failed to re-package
resources. See the Console for details.
D:ProgrammingIDEadtsdkbuild-tools21.0.0aapt.exe package
--auto-add-overlay -v -f -m -J gen -M AndroidManifest.xml -S "res" ...

I really need some help. I am about to release the 2nd alpha version of my app to test the play services. but this error keeps on popping? do you know How can I get rid of this. tried removing androidmanifest like other said. reimporting but it is still there?