I\'m trying to connect my app to Google play service to access Google Drive but It showing me connection failed with statusCode SIGN_IN_REQUIRED.
As I see most of the answer above are right, still if you could not able to solve the problem. Here are the things please check with your development environment
If you have switched between two different systems(pc/laptop), please generate another SHA1 key for each system and update on Google developer console
If you have not switched between two system still you face the issue then, make sure in your manifest application Id is matching with package name you have given in Google developer console
Don't forget to enable Drive API in Google developer console