Office / Outlook 365 Authentication Couldn’t Be Completed, Blank page

We’ve had issues with Offce 365 running on MAC.

Outlook couldn’t be configured with Office 365.  After entering email address we would get:

Connecting to Office 365

Authentication Couldn’t be completed

Try again

When Outlook was configured and not receiving emails, a window would mysteriously pop-up and close.

Attempting to open other office 365 programs like Word and Excel would open a blank white window.

Troubleshooting:

We removed outlook profile and recreated

We delete credentials in key chain

updated MAC OS

Done many other things to no avail.

But when we tried the MAC outside the office network (at home or over hotspot), everything worked fine.

Conclusion, the issue was network, we will be checking the Sonicwall firewall at the office and DHCP server, IPv6 to see which one caused the issue… to be continued later….