Some customers in AWS us-east-1 may observe a small number of gRPC UNIMPLEMENTED errors

Incident Report for Temporal

Resolved

Some customers in AWS us-east-1 may observe a small number of gRPC UNIMPLEMENTED errors returned during the time period 15:00-15:30:00 UTC.

This issue was investigated and identified as being related to a deployment in the affected region that has been rolled back - no further impact is expected.

Posted May 27, 2026 - 15:00 UTC