Windows Servers

Microsoft 365 apps will not open

Fix Word, Excel, or Outlook failing to open on a Windows server by signing out of your profile and back in.

Sometimes a Microsoft 365 app such as Word, Excel, or Outlook will not open. This is a known Windows behaviour that Microsoft has acknowledged, and it affects both Windows and Windows Server.

Why it happens

It usually happens when an app is opened and then closed again almost straight away, though it can also occur on its own. Windows does not fully close the app, so it keeps running in the background and blocks a new window from opening.

The fix

Signing out of your Windows profile and back in clears the leftover process.

  1. Save your work and close all open apps.

  2. Select the Start button, then select your user profile picture.

  3. Choose Sign out.

  4. Sign back in from the sign-in screen, or through your usual remote desktop connection if you reach the server over RDP.

Your apps should now open normally.