I would like to consult, because when I want to register a new user in one of my applications, firebase, at times totally random (now almost permanent) I get an error of "no valid registration ids" the FCM API, so I do not register any new user, and yet, I did not make any changes in the last months for this to fail, it is more, initially (do not start the project myself), corregi the passage of terms to build the corresponding json and had started working correctly, I pass the sender id in the project_id as many people explain it, and the registration_id is the id that returns firebase for the record, and it returns that error once I try to send the json for the record. Attached capture of the corresponding code. try to find a solution by google, but everything I find is maximum of October 2017, nothing new, I do not know if it will be because it is not used as much or because there are really no more problems lately. the language used for all this, is C # since this fragment of code belongs to a backend that groups applications to handle the subscriptions of the notifications
