Microsoft has released an out-of-band update for Windows 11 version 23H2 to address issues caused by a previous security fix, KB5073455. The patch resolves problems with frozen applications and errors when interacting with cloud storage services like OneDrive or Dropbox. The issue specifically affected Outlook users storing PST files via these services, resulting in them becoming stuck and necessitating a shutdown or reboot for resolution. The KB5078132 update is now available for download from Microsoft's Update Catalog or will automatically install on systems that have either KB5073455 or KB5077797 already installed.

KB5078132 Outlook fix for Windows 11 23H2

Microsoft just released an out-of-band (OOB) update for Windows 11 version 23H2. This patch specifically targets issues stemming from a previous security fix, KB5073455.

Earlier this month, some users noticed problems after installing that January 13th security release (KB5073455), along with the OOB update KB5077797 it incorporated. Specifically, applications could freeze or show errors when interacting with cloud storage like OneDrive or Dropbox.

This hitch was especially annoying for Outlook users storing PST files via OneDrive or similar services. The email client would sometimes get stuck and refuse to reopen unless you forced a shutdown or rebooted the system.

The KB5078132 update arrives as a welcome fix, automatically updating systems that already have either KB5073455 or KB5077797 installed. You can also grab it yourself from Microsoft's Update Catalog if you prefer to manage things manually.

For more information, check out the linked support article below:

January 24, 2026—KB5078132 (OS Build 22631.6495) Out-of-band - Microsoft Support

January 24, 2026—KB5078132 (OS Build 22631.6495) Out-of-band - Microsoft Support