Sigma Computing change history: Users unable to enter edits to Workbooks

Sigma Computing reported a major incident in which users who had recently edited a Workbook received errors when making further edits. The recorded start is 2023-10-06 20:27 UTC, but resolution is listed earlier, at 2023-08-09 22:00 UTC; duration is unknown. Engineering completed a postmortem and linked an RCA on Sigma Community.