Processes in Microsoft 365 for setting up Office apps, redeeming product keys, and activating licenses.
Dear respected Mike_2409,
Good day! Thank you for posting to Microsoft Community. We are happy to help you.
I’m sorry you’re having a problem but based on your description we can work together to resolve it.
For the situation you encountered, we deeply understand the inconvenience caused and apologize for it.
As per your description, you can use Office on your Mac OS Big Sur. But the latest version of Office 16.82 did not support on your Mac OS Big Sur.
You can use old Office version 16.77 on your Mac OS Big Sur(this is last/final version for Mac OS Big Sur).
You can download the installer version 16.77 from this link Office suite (with Teams) on your MacOS Big Sur 11.7.2.
Also, you can download the installer version 16.77 from this page: Update history for Office for Mac as well.
For your reference according to Microsoft article Upgrade macOS to continue receiving Microsoft 365 and Office for Mac updates, the September 2023 update (16.77) is the last build to support macOS Big Sur.
Summary:
Since the latest Office version doesn't support MacOS Big Sur 11.7.2. First, you'd need to delete the wrong version:
For your reference: Uninstall Office for Mac - Microsoft Support
Then for MacOS Big Sur 11.7.2, you can download 16.77 compatible version of Office:
Office package (with Teams)
Office package (without Teams)
Appreciate your patience and understanding and thank you for your time and cooperation.
Sincerely,
Waqas Muhammad