Hi nvrenuf,
I fully understand the inconvenience this issue caused. Please refer to the following steps to narrow down the root cause of this issue:
1. Do a fully reset on Safari, and check to see if the issue persists.
2. If there is any chance, you can login to Office 365 portal and download Office 365 ProPlus using the other browsers, for instance, FireFox or Chrome on MAC.
We have also noticed there are some other community members reported the similar issue if using Safari to login to Office 365 portal. Here I'd like to collect your tenant information for further investigation, I have sent a private message to you to collect your domain information, and you can check private messages with the following steps:
• Go to the Your details section on the right side of the community site.
• Click Private messages.
• Click the subject title of the response to read the message.
• You can reply by using the form in this display.
• Click Submit Reply.
Thanks,
Allen Qiu
