Getting "Moving file failed" error on integrating with admob!

When im building in order to test on my device after integrating admob, i get this odd error saying it couldnt find soem path while moving. pleaes help me resolve this issue.thx

That .aar file probably doesn’t have any classes.jar inside it. The build process assumes that .aar libraries always contain compiled code inside them (classes.jar) so it attempts to move that file as part of the build process.