Forum Discussion
Problems with Office 2013 and SharePoint Online
Hi, We have an estate of approximately 4000 machines with O365 E3 licenses currently using Office 2013. Late last week users started reporting that they couldn't open documents from SharePoint O...
Not sure I can help but can I check just one thing, are you running any these Office 2013 versions -Professional Plus, Professional or Standard editions with Service Pack 1? Those are the only versions supported still, while support for 2013 versions of Office 365 ProPlus ended February 28, 2017, which you probably know already.
I would open a service request straight away if this is having a big impact and get confirmation of what the issue might be.
Update: See if there is anything here that might be relevant - https://support.microsoft.com/en-us/help/2834958/can-t-sign-in-to-an-office-app-by-using-a-work-or-school-account. Are you using MFA by the way?