

If yes, untick it, restart the Mac and do a test to see the result.

I suggest you open System Preferences>Network>Advanced>check if the Auto Proxy Discovery is ticked. I have already contacted Microsoft Office support and they replied " From the error message, it sounds like a network issue. It appears the message "No network connection - Please check your network settings and try again." even if I am fully connected. I am not able to sign in from my computer to any of the Office applications (while I can from my smartphone).
