All of a sudden, we are getting an error authenticating with Nest and Firebase. The error code is 9999, and the message is "blocked". The source code has not changed on the app side, so it seems like something has changed on the server side.
I see a similar issue here, however they are getting a message of "too many requests", instead of "blocked".
Can anyone help us resolve this issue? Thanks.
This error occurs when you have too many concurrent open connections to Nest using the same access token. This is a different issue to "too many requests" issue which, as indicated, is to protect the battery in the thermostat.
It seems that you may be opening up Firebase or REST streaming connections and not closing them properly before opening up a new connection. Once a Firebase connection is open you should use this connection for reading and writing any new data and open a new connection only if when this connection is severed.
Could you please post sample code on how you are handling opening, closing and using the connections? Your sample code will help analyze the specifics of the issue.
来源：https://stackoverflow.com/questions/28815002/firebase-error-code-9999-blocked