What does it mean when Firebase Messaging encounters an error and only resolves when the server is restarted?

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When Firebase Messaging encounters an error and only resolves when the server is restarted, it likely indicates that there is a server-side issue with the Firebase service or with the connection to the Firebase server. Restarting the server essentially refreshes or resets the connection to the Firebase server, resolving any errors or issues that may have been preventing messages from being sent. This could be caused by a variety of factors, such as network connectivity issues, server load or bottleneck issues, or even bugs within the Firebase service or SDK. It is important to investigate and address the root cause of the error to prevent it from recurring in the future.