The Vault login errors in the US region were caused by a database failover in the US-EAST-1 region at 10PM PST. The failover was caused by a scheduled data update that was being performed by the engineering team. The failover took approx. 15 minutes to process. Normally a failover is significantly faster, however this particular scenario required additional processing time. All application services became available at approx 10:30PM PST. The Keeper DevOps team will be making necessary changes to prevent this extended failover processing from occurring in the future. Vault Offline Mode was available to all users during the outage.