Word Save As PDF Bug Silently Saves Files to Wrong Folder, How to Fix It

If you use Word 365 to save documents as PDFs to SharePoint and perhaps other locations, your files may be vanishing. Microsoft has confirmed a bug in version 2609 that silently drops PDFs into a hidden cache folder on your PC with randomized filenames, and gives you no warning. Here’s how to check if you’re affected and what to do until Microsoft issues a fix.

Microsoft says that after updating to Microsoft 365 for Windows version 2609 build 16.0.20430.x, users may be unable to save Word documents as PDFs to SharePoint Online locations.

No error appears, and the file is instead saved to the C:\Users\username\AppData\Local\Microsoft\Windows\INetCache\Content.MSO folder with a random file name.

Microsoft’s status is “Workaround”, which means there is no fix yet.

This is the worst kind of bug: a silent one. Word acts like the save worked, you close the document, and anyone who opens the SharePoint folder later finds nothing there. Neowin has good reporting on this, more than Microsoft’s terse note.

Exactly what triggers it

According to Microsoft, the issue only occurs when using Save or Save As, choosing the PDF file type, and selecting a SharePoint location.

The “random name” isn’t subtle. One user reported files named things like 1f10f000 and 458d72b7 instead of the original file name. So even if you go looking, you won’t find “Q3 Sales Targets.pdf” by searching for it.

Don’t assume it’s only SharePoint

Microsoft’s note mentions SharePoint Online, but the original report came from someone saving to a network drive. That user said Word saved a PDF of a network drive document to the Content.MSO folder instead of the source folder, running Version 2609 Build 16.0.20430.20032.

If you save PDFs anywhere other than your own hard drive, treat this bug as your problem too.

Are you affected?

Check your Word version: go to File | Account and look under About Word. If it says Version 2609 with a build starting 20430, you’re in the affected group.

Microsoft’s own support page lists the whole 16.0.20430.x build family, so regular Current Channel users will likely get it as 2609 rolls out more widely.

How to find your missing PDFs

The Content.MSO folder is hidden, so you won’t find it by clicking through File Explorer. Paste the path directly instead:

• Open File Explorer and click in the address bar.
• Paste %LOCALAPPDATA%\Microsoft\Windows\INetCache\Content.MSO and press Enter.
• Sort by Date modified so your most recent files are at the top.
• Look for PDFs with random names created around the time you saved.
• Open each to check it’s the right one, rename it properly, and move it to where it should have gone.

Do this soon. INetCache is a temporary cache folder. Cleanup tools and Windows itself can empty it, so don’t treat it as somewhere your files are safe.

There’s also a privacy angle. If you were saving confidential documents to a secured SharePoint site, copies are now sitting in an unprotected local folder. Once you’ve recovered them, delete the stray copies.

How to make PDFs safely until Microsoft fixes it

Microsoft’s official workaround: save to an alternative location, or use Export | Create PDF/XPS Document. Your options, best first:

• File | Export | Create PDF/XPS Document. This is the one to use. It produces the same quality PDF as Save As, links and all, and avoids the bug.
• Save the PDF to your own PC first, then upload or drag it into SharePoint. Clunky, but reliable.
• Print to “Microsoft Print to PDF”. Users report that printing the same document to PDF still worked normally. It’s a fallback only, since printed PDFs typically lose clickable links, bookmarks, and accessibility tags.

Whatever you use, open the SharePoint folder afterward and confirm the PDF is actually there, at least until Microsoft marks this fixed.

Should you roll back Office?

You could fix the bug by rolling back to the previous version, 2608 build 20326.20072. That works, but for most people it’s overkill. Rolling back means running a command-line tool and pausing updates.

For almost everyone, simply switching to File | Export is the better answer. It’s one extra click and no risk.

If you do manage PCs for a team, check which devices are on 16.0.20430.x builds, especially those that export PDFs to SharePoint, and tell users to use File | Export for PDFs until Microsoft marks the issue fixed.

More Office Bugs, Fixes and File Safety

This isn’t the only recent update to break something important. KB5002907 Broke Office 2016 and 2019: How to Get Office Back deactivated or uninstalled perpetual Office licences entirely, and the Excel Copy Paste Bug: Is Your Office Version Fixed Yet? tracker covers Microsoft’s painfully slow response to a separate September patch that silently killed copy and paste in Excel.

If you’re wondering whether to let Office update itself at all, Microsoft Office Updates: A No-Win Scenario and How to Stay Safe lays out the trade-offs between patching early and waiting for someone else to find the bugs first.

The Export workaround in this article gets you a PDF, but there’s more to getting good output. PDF Save As or Print: Best Methods Explained walks through the differences between Save As and Print to PDF, and Free PDF Merge and Split on Windows or Mac covers what to do when you need to combine or trim the results — no Adobe subscription required.

This bug also exposed how files can quietly end up in places you didn’t choose. Secret stuff saved on your OneDrive reveals the hidden folders Microsoft creates on your cloud storage without telling you, and Five changes to make Microsoft Office saves more reliable covers the settings worth changing so you’re less likely to lose work the next time something goes wrong.