Botched Windows patch KB 3178690 freezes, crashes Excel 2010

If you use Excel 2010 and your spreadsheets are suddenly acting strange—freezes, crashes for no apparent reason—you likely have Windows Automatic Update turned on. Last Tuesday, as part of its usual Patch Tuesday celebrations, Microsoft pushed a patch,KB3178690, that causes recalculations in Excel 2010 to freeze or crash the program.
The only solution at this point: Uninstall the patch.
Poster gneJim first raised the alarm on Thursday on the Microsoft Answers forum:
KB3178690 causing excel 2010 to crash
I have had to remove this update from approx. 4 machines (3x Win7, 1x Win10) this morning as Excel 2010 kept crashing out when trying to update SQL queries.
By Friday night, Microsoft employee Freya had confirmed the problem:
Issue summary: After installing KB3178690 in Excel 2010, calculation triggered either by code or user interaction in the workbook may result in a hang or crash. We released KB3178690 on March 14.
We are urgently working on a fix and I will keep this thread updated when we have more information.
Bewildered Excel 2010 users have continue to wonder throughout the weekend why their spreadsheets are suddenly crashing. To date, there’s no fix for the problem, other than uninstalling the patch.
Microsoft has graciously “unchecked” the update, so it doesn’t continue to install automatically on Windows 7 and 8.1 systems. Those of you running Windows 10 will have to uninstall the patch, then take the additional step of using the wushowhide utility to prevent the patch from being installed again.
As of Monday morning, the patch is still available in the Update Catalog and is being distributed as an unchecked Important update. But oddly–and without explanation–the Catalog version is dated Friday, March 17.
It’s hard to imagine how this automatically updated security patch got through Microsoft’s testing.
On the other hand, this demonstrates the advantage of releasing patches separately. If the Office 2010 patches had been bundled–as is currently the case with Windows 7, 8.1, and 10–you would’ve been forced to back out the entire bundled batch to fix this one blunder.
Discussion continues on the AskWoody Lounge.