Hi PeterBarnes,
Based on your post, I’d like to collect the information below to narrow down the issue:
1. Whether the Office 365 App here is Office ProPlus downloaded from Office 365 portal?
2. I notice “asked to sung when trying to open Word or Excel app” as you mentioned, do you mind provide us with a screenshot of the page?
3. Please offer us a screenshot of the error message you mentioned.
4. I’d like to confirm if the issue occurred on every user in your subscription.
Please get back to us with the information requested above and we will glad to assist you.
Thanks,
Lawliet Xu