FCM getting MismatchSenderId

Question

I have an application that uses Google FCM for sending push notifications.

When i send a push notification to a group of users, i get a response of MismatchSen

Answer 1

THIS WORKED FOR ME:

• CHECK WHICH FIREBASE PROJECT YOUR CURRENT ANDROID PROJECT IS LINKED TO AND USE Server Key FROM THAT PROJECT.

I was using Server key from a different firebase project(say Project 2). I used the same server key as linked with my android project(Say Project 1) and it worked. In my experience, using one firebase app for one entire android project seemed to fix the problem.