Hi @Laurence Hauben
Thank you for reaching out to the Microsoft Q&A forum.
Based on the information you described, I understand that you are suddenly unable to save Excel documents because the Save option is greyed out. You initially suspected that your Microsoft 365 license might have expired; however, you are still able to save and edit Word documents under the same installation. Additionally, when checking About Excel, you noticed that Excel is licensed under a different email address.
Since Word is working normally while Excel is not, this issue may be caused by the device being signed in with multiple Microsoft accounts, and Excel is currently associated with an account that does not have an active license.
To troubleshoot this, I recommend the following steps:
-Verify which account has an active license: Please verify which account still has an active subscription.
-Remove existing Office license files on your Mac: Once you have identified the correct licensed account, please follow Microsoft’s official documentation to remove Office license files on a Mac. This helps clear cached credentials and resolves account conflicts between Office apps. After removing the license files, restart your Mac, then open an Office app and sign in again using the account that has the active Microsoft 365 license.
I hope this information helps resolve the issue. If you need further assistance, please let me know, and feel free to share any additional details.
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