404 FILE NOT FOUND

Thank you for your reply, Dylan. With these days' discussions on community, we have realized that this 404 error is not a personal issue but a widespread hot issue affecting Office users over the world.

This issue is causing users occasionally unable to open files in OneDrive, or losing their notebooks in OneNote. So far, this issue has not been fixed yet. We are still gathering more information about this problem. We have to suggest you make a good back up of your important data during this period. Considering you seem to be able to access your file from web now, you'd better download your important files to your local disk, instead of viewing them in OneDrive. This can reduce the chance that you are affected by this problem.

Sorry for the inconvenience. Once we get any updates on this issue, we will let you know as soon as possible.

Best Regards,

William.Y | Microsoft Community Support Specialist

Thanks for your response. I cannot open files via double clicking or with the from the "Open" page. I have signed in and out but this didn't seem to help.

Something I did notice, I'm able to open the files from the Home tab.

Hello Dylan,

Welcome to the Microsoft Community.

I’m sorry to hear you’re having trouble with your files. The “404 FILE NOT FOUND” error usually indicates that the file path is incorrect, or the file has been moved or deleted. To help us determine your issue more accurately, could you give us some further clarification on how you open the files in office application? Are you opening them from "Open" tab, or simply just double clicking on files on your desktop?

If you cannot open files via double clicking your mouse left key, it indicates that some problems are affecting your Office application. While if you can open normal document files via double clicking, but you cannot open files from the "Open" page, you need to check your account status in Office.

If you are not signed into the correct account, you will lose access to certain files which are saved under a different account.

You can try to sign out of your account, and sign back in again later to check if your issue persists.

Kindly please share your results with us. We will do further research to help you with our best efforts based on your additional information.

Best Regards,

William.Y | Microsoft Community Support Specialist