Android installation failed

[cirodevita]

When i try to build app i get this error:

FAILURE: Build failed with an exception.

• What went wrong:
  Could not resolve all files for configuration ':releaseCompileClasspath'.

Could not resolve br.com.mobilemind.api:mobilemind-droid-util:2.1.
Required by:
project :
Could not resolve br.com.mobilemind.api:mobilemind-droid-util:2.1.
> Could not get resource 'http://nexus.mobilemind.com.br/repository/mobile-mind-m2/br/com/mobilemind/api/mobilemind-droid-util/2.1/mobilemind-droid-util-2.1.pom'.
> Could not GET 'http://nexus.mobilemind.com.br/repository/mobile-mind-m2/br/com/mobilemind/api/mobilemind-droid-util/2.1/mobilemind-droid-util-2.1.pom'. Received s
tatus code 502 from server: Bad Gateway