Resolved
This incident is resolved. Browser creation and connections are healthy again as of 6:27pm PT. If a browser created between 5:44pm and 6:27pm PT still won't connect, delete it and create a new one.
Monitoring
As of 6:27pm PT, a fix has been deployed and browser creation and connections have recovered. Browsers created between 5:44pm and 6:27pm PT that won't connect should be deleted and recreated. We're monitoring.
Identified
Since 5:44pm PT (01:44 UTC), some requests to create a browser are failing with 529 capacity errors, and some newly created browsers are rejecting CDP connections. We've identified the cause and are rolling out a fix. If a browser created during this window won't connect, delete it and create a new one. We'll post another update once it's resolved.