Beginning at 10:14 AM ET today (September 14, 2021) and continuing for approximately 45 minutes, the Arbitrum Sequencer was offline. Funds were never at risk, but the submission of new transactions stopped during the downtime. Arbitrum One is still in its beta phase, and we will do our best to minimize downtime.
The root cause of the downtime was a bug causing the Sequencer to get stuck when it received a very large burst of transactions in a short period of time. The issue has been identified and a fix has been deployed.