Configuring preferences and options in Outlook on the web for business
This matches a known Outlook for Microsoft 365 issue where Outlook can crash when composing or authoring, especially if an older Office language pack is installed alongside a newer Microsoft 365 build.
Check this first:
- Open Windows Event Viewer and look in the Application Log for Event 1000 or Event 1001.
- Confirm whether the faulting module is a language DLL such as mscss7it.dll, mscss7ge.dll, or another mscss7xx.dll file.
- If the module version is something like 16.0.4288.1000, that indicates an older MSI language installation.
Fix steps:
- Go to Windows Settings > Apps > Installed Apps.
- Find the old Office language installation and uninstall it.
- Reinstall the language pack by following Step 2: Configure Microsoft 365 language in Language Accessory Pack for Microsoft 365.
Important: uninstalling and reinstalling language packs changes Office language components, so close Office apps first before making the change.
If the crash happens specifically while drafting or typing, this is the documented workaround in the current known issue.