Last month, Microsoft announced a serious bug affecting Word, Outlook, and OneNote that could cause the apps to crash just by typing. Fortunately, Microsoft has developed a fix that will be released next week.
On August 15, Microsoft disclosed that a version mismatch in Microsoft 365’s Office apps was behind the crashes. “After updating to Version 2407 Build 17830.20138 or higher, users may find that Outlook, Word, or OneNote closes unexpectedly when typing or performing tasks like spell check,” Microsoft explained.
The issue has now been diagnosed, with Microsoft stating, “The crash issue is caused by a version mismatch between Office 2016 proofing tools and Office language packs (M365 apps for Enterprise). These proofing tools may be remnants from older installations or part of an Office suite migration. Running Office 2016 side by side with M365 apps isn’t supported because they use different installation technologies.”
The fix is already accessible to Microsoft 365 Insiders via Version 2409 (Build 18021.15000) in the Beta Channel and Version 2409 (Build 18025.20000) in the Current Channel Preview. Standard Office 365 users will see the update released with Version 2409 (Build 18025.20000) on September 24.
The patch resolves issues with outdated proofing tools and mismatched language pack versions. If you’re eager for an immediate fix, you can find a workaround by uninstalling and reinstalling the language pack on Microsoft’s support page.