There is a strange bug in Office 365. Once in awhile it will think that someone else has logged into Office on your computer (VDI) - even though you are one logged on.
You have to sign out then back into Office to straighten this out.
1. A box like below will pop up when you open Word, Excel, or Outlook. Click the x in the upper right corner to cancel it.
2. Now, in Work, Excel, or Outlook, click File then Account.
3. On the Account page, click Sign out.
3. Click Sign Out on the button that pops up. Your Office application will log you out of your Microsoft online account.
4. Then click the Sign In button. Log in with your e-mail address and network password; you may not even need to enter your password. This time your Officeapplication will load correctly.