Broke 0.2 Vistas Fixed officially acknowledged Dec 11, 2018 their #74 worst broke on record

Microsoft Access updates itself into refusing its own databases

December 2018 Office updates broke linked-table queries in Access

↳ caused by December 11, 2018 Office security updates

The market's verdict: -4.4% on MSFT in the week after.

Status: Fixed. Working as intended, eventually.

What actually happened

December 2018 Office security updates made Microsoft Access throw "Invalid Argument" errors on queries that touched linked tables with multi-value lookup fields. So, Access broke Access. An emergency hotfix followed within weeks. Database people described the experience as "very Microsoft."

This one is officially acknowledged.

Were you affected? Unbreak it

Out-of-band hotfix shipped January 2019

Microsoft has acknowledged this issue; a fix ships in an out-of-band or next cumulative update. Check Windows Release Health before manual workarounds.

They did it more than once

Later, again: The September Office update quietly broke copy and paste in Excel (Sep 2026)

An Office update breaking the most basic function available: 2018 Access, 2026 Excel.

Timeline

Dec 11, 2018 Fixed Microsoft shipped a fix.