try safe mode.
How to start Office for Windows applications in Office Safe Mode
Use one of these methods to start an Office application in Office Safe Mode on a Windows PC:
Press and hold the CTRL key to open an Office application
Use the /safe option to open an Office application
If you can’t start a Microsoft Office application in Office Safe Mode or you have recurring problems opening applications in normal mode, you can try to repair Office. For more information, go to Repair an Office application
if that fails Id suggest https://www.libreoffice.org/
Tried the safe mode but still got the pop up window.