Dear cmkallen7654,
Good day! Thank you for posting your query in our community.
Based on your description, when you try to open Excel workbook from Excel Online, an error pops up. And the problem happens on multiple devices and internets, we assume the problem may be related to the backend.
Given this situation, the only way we can think of to troubleshoot the issue is to report the issue to the related Team. So we suggest you can open a ticket to see if support there could help you. The support team there has the correct escalation channel for this case. This is also the most efficient way in handling this kind of issue. You can check if the engineers there can help you recover the content.
- If you are using work/school account, you can contact the administrator in your company/school and follow the steps in the article to open a ticket.
- If you are using personal account, we suggest that you can contact phone support on this page: Contact Microsoft Support.
Your understanding and patience will be highly appreciated.
Sincerely,
Jazlyn | Microsoft Community Moderator