We are aware of an issue connecting Galaxy of Heroes to Facebook, particularly with the “find allies” feature. Players who have linked their game to Facebook and are attempting to search for allies among their Facebook “friends” will see a message stating “App is in Development Mode.”
We are working on a fix for this issue. In the meantime, players can log in and make progress without issue. However, social interactions that use Facebook will encounter errors. Also, players not logged into Facebook cannot link their accounts until we resolve the issue.