New Outlook for Windows (olk.exe) v1.2026.317 / 1.2026.325 Crashes Linked to olkmain.dll

We have identified an increased rate of crashes affecting the olk.exe process in New Outlook for Windows, specifically versions 1.2026.317 and 1.2026.325. This behavior began emerging at the end of March and is now visible across a growing number of environments, consistently faulting in olkmain.dll.

The crash has been observed across more than 400 organizations and is classified as medium severity. Given Outlook’s role as a primary, user-facing communication tool, instability in this process is likely to disrupt daily workflows and impact end-user productivity.

Some online reports suggest that clearing the Outlook local cache using olk.exe --clearLocalState may temporarily mitigate the issue. This appears to provide short-term relief while a permanent fix is pending.

The pattern and timing of these crashes suggest the issue is tied to changes introduced in recent Outlook releases. A future update will likely address the underlying cause as the behavior becomes more widely identified.