Back in August, Microsoft had confirmed that Office apps like Outlook, Word, and OneNote, would crash when typing, or spell-checking, among others. The company explained back then that the issue was potentially the result of out-of-date language packs leading to a compatibility conflict. A temporary workaround solution was provided at that time.
Fast forward to now, Microsoft says it has fixed the problem and has also explained in detail what caused it. It writes:
CAUSE
The crash issue is caused due to version mismatch between Office 2016 proofing tools in coexistence with Office language packs (M365 apps for Enterprise). These proofing tools are probably old traces from previous installs or part of Office suite migration.
Coexistence of Office 2016 side by side with M365 apps is not supported due to different installation technologies of same version. For more information, go to Office installed with Click-to-Run and Windows Installer on same computer isn"t supported.
The Office build numbers that resolve the issue have also been listed:
STATUS: FIXED
This issue is fixed in the following builds:
Beta Channel: Version 2409 (Build 18021.15000)
Current Channel Preview: Version 2409 (Build 18025.20000)
Current Channel: Version 2409 (Build 18025.20000) ETA 9/24/24
Hence, if you have been experiencing such crashes, you are advised to update your Office to the versions listed above.
In addition, Microsoft has also detailed how the resolution addresses two such compatibility conflict issues. It says:
This fix addresses two problems:
Older versions of proofing tools installed with M365 Office.
Office 2016 proofing tools are offered for download via standalone per-language installers. Even if they may appear to function correctly, however, using these Office 2016 proofing tools together with later versions of Office is not supported.
This fix prevents a crash in Word, Outlook, OneNote and PowerPoint caused by this unsupported installation scenario. Users are strongly recommended to uninstall the Office 2016 proofing tools if they are using a later version of Office and to install the appropriate Office language packs instead. Office language packs update automatically along with the version of Office they are paired with.
Current versions of M365 Office where the language pack version is different from the main installer.
This fix also addresses problems when M365 Click to Run language pack version is different from the main installer. The fix will prevent future occurrences of the issue. If you still see the issue after the fixed build you will need to repair Office per the workaround guidance below.
You can find the support document documenting the issue here on Microsoft"s official website.