Hi @Robert Pearce
Based on the information you shared, I understand that you are using macOS Ventura 13.7.8 and are having trouble installing Microsoft 365.After doing some research, I found that the September 2025 update (version 16.101) is the last Microsoft 365 build that supports macOS Ventura (macOS 13). Newer versions require a more recent macOS and therefore cannot be installed on your system.
In this case, please access the link below and download/install Microsoft Office version 16.101 instead:
Update history for Office for Mac

Thank you, and please let me know if you need any further assistance.
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