According to the research, following Windows updates that were released on January 13, 2026, users with Outlook profiles that had PST files stored on OneDrive started reporting that Outlook froze and failed to exit properly. Issues included sent emails not showing in the Sent Items folder and Outlook re-downloading messages. Microsoft confirmed the problem that affected a wide range of Windows 10 and 11 versions and Windows Server editions, and mostly had no fix except recommending that users move their PST files out of OneDrive completely. A patch was later issued, but the incident left a lasting mark on how IT administrators think about where PST files live. (Source: Microsoft Support — Classic Outlook profiles with POP accounts and PSTs hang after Windows updates on January 13, 2026) https://support.microsoft.com/en-US/Support/known-issues/classic-outlook-profiles-with-pop-accounts-and-psts-hang-after-windows-updates-on-january-13-2026

The main problem, as Microsoft and outside reporting described it, came down to a conflict between OneDrive’s file sync behavior and Outlook’s need for exclusive, uninterrupted access to a PST file while it’s open. Storing a PST in a synced folder always had risk, this update made the risk immediate for a large number of users at once.

As for IT Teams, the news renewed a basic but often-skipped practice: keeping PST archives in a genuinely local, unsynced location, and maintaining a different backup copy rather than depending on OneDrive sync as a substitute for one. WholeClear 11.0 fits into the workflow on the conversion and backup side – as its PST tools handles folder structured export and format conversion for local archives, and its cloud module downloads a local copy of Microsoft 365 or IMAP mailboxes independent of any sync layer.

“PST files were never designed to sit inside a sync folder”, said a WholeClear Product Representative, “A local unsynced backup isn’t a workaround for that problem – it’s just how these were always supposed to be handled.”

Media Contact
WholeClear Support Team
[email protected]
https://www.wholeclear.com