After reading 100 threads and googling, I am still confused by this error message.
I am currently using Firebase Cloud Messaging, and in a very short time I am trying to get my token from Firebase to send messages to my server. I tried both of these methods:
String token = FirebaseInstanceId.getInstance().getToken(mySenderId, "FCM");
String token = FirebaseInstanceId.getInstance().getToken();
So in the logs I read the following:
E/FirebaseInstanceId: Token retrieval failed: TOO_MANY_REGISTRATIONS
java.io.IOException: TOO_MANY_REGISTRATIONS
According to other messages and replies, this is the reason “Too many installed applications on the device that are registered in C2DM / GCM / FCM”. I also read that the device has a restriction of "Max 100 GCM / FCM registered applications."
But this is not just true, is it? I mean, this may be true, but that is not the whole answer to this question. I constantly work and test various devices, and my current device does not have 100 applications registered in FCM. In fact, my device doesn’t even have 100 applications installed, far from it!
Is there a way to manage previous registered devices and tokens? I tried to run the following code with no luck:
FirebaseInstanceId.getInstance().deleteInstanceId();
I tried to hide information from various sources (including documentation), not knowing how it works. I had the same problem with the old C2DM some time ago, as well as with GCM recently. A few days ago, I teamed up with Firebase to use its features, rather than thinking about improvements in it, but it still echoes me.