This incident has been resolved. Facebook account access and message processing are operating normally. We have added safeguards and additional monitoring to prevent a recurrence. We apologize for the disruption.

A fix has been deployed and error rates have returned to normal. We are monitoring the service closely to confirm full recovery.

We have identified the root cause as a bug in our inbound event processing that could leave a service in a bad state. A fix is being prepared and deployed.

We are investigating reports of "Account temporarily unavailable" errors affecting Facebook account access. Some users may also see delayed or failed message processing. We will share an update shortly.