I have an Android app that receives push notifications from Google Cloud Messaging. The app worked for several years.
It has been brought to my attention that push notifications no longer work on Android. Upon reviewing logs, I'm finding a "MismatchSenderId" error when POSTing to https://gcm-http.googleapis.com/gcm/send.
I searched all my projects with my Google accounts and cannot find anything under this SenderID.
Is there anything that can be done to restore this project number?