Microsoft has confirmed a bug in Word version 2609 for Windows that misdirects PDF files saved to SharePoint Online, depositing them instead in a local cache folder with randomly generated filenames whilst displaying no error message to alert the user. The issue is particularly troublesome as affected users may be unaware their documents have not been saved to the intended location, compounding Microsoft's recent catalogue of software problems.

The affected files are redirected to C:Users[username]AppDataLocalMicrosoftWindowsINetCacheContent.MSO with random names, and Microsoft confirmed the issue occurs specifically when using Save or Save As with PDF format and a SharePoint Online destination. The company has not yet provided a timeline for a fix, though some users have reported that reverting to an earlier version resolves the problem. This latest bug is part of a troubling pattern: Microsoft's recent updates have inadvertently deactivated Office 2016 and 2019, caused paste malfunctions in Excel, triggered severe Windows stability issues, led to data loss in Microsoft 365, and created File History backup problems—reflecting systemic quality assurance challenges across the company's products.