If you noticed that certain Office apps are now crashing more than usual, that is because a bug in recent releases is causing Outlook, Word, and OneNote to crash when typing, spell-checking or performing other authoring tasks and actions. Microsoft has now confirmed the problem and published a support document with all the details.
According to Microsoft, the problem occurs in Office version 2407, build number 17830.20138 and higher. To confirm that your system is affected, launch Event Viewer and look out for Event 1000 or Event 1001:
You can confirm if this is the issue when by looking at the Windows Event Viewer Application Log for Event 1000 or Event 1001, and the following event details:
Faulting application name: OUTLOOK.EXE, version: 16.0.17830.20138, time stamp: 0x66aaad8c
Faulting module name: mscss7it.dll, version: 16.0.12527.20122, time stamp: 0x5e439ea1 Exception code: 0xc0000005
Fault offset: 0x000000000003e518
Faulting process id: 0x0x51B0
Faulting application start time: 0x0x1DAE97DD89190C3The faulting module name will vary depending on what language packs you have installed. For example, mscss7it.dll for Italian, or mscss7de.dll, for German, with others listed here, Language identifiers and OptionState ID values in Office 2016.
Microsoft says that the root of the problem may be an out-of-date language pack:
This issue may occur if the language pack version is not updated to the current version. If you check the version of the C:\Program Files\Microsoft Office\root\Office16\ mscss7xx.dll it should be a build closely matching the Office version but might not match exactly.
Fortunately, you can mitigate the problem relatively easily. To fix the issue while Microsoft and the Office team are investigating it, perform an online repair of your Office apps or re-install your language packs. If you do not know how to do that, check out the official "Repair an Office application" and "Language Accessory Pack for Microsoft 365" documentation.