Dear Blair Waldman,
Thanks for using Microsoft products and posting in the community.
I understand that you are getting an error when inserting a pdf file in excel. I understand how you feel and will do my best to answer your questions.
According to your question we carried out a test, in Windows11 Microsoft365 EXCEL can be inserted into the normal PDF file, but also be able to open the normal. But when the PDF file to open when inserting this document will appear with your page the same error.
If you did not open this PDF file, could you share more information with us in order to better troubleshoot the error?This is because there are many reasons for this problem. Excel may have trouble embedding certain PDF files, especially if they are large or contain complex elements. If either the Excel file or the PDF is corrupted, it can lead to this error.
1.Can you give me a screenshot of your Windows system? Press the Windows key + R to open the Run dialog box. Then type winver and press Enter. What exactly is your excel version? Can you open File - Accounts and send me a screenshot of account page?
2.To confirm whether it is caused by PDF file corruption, can you open PDF files normally? Do you have this problem when you insert other PDF files?
We look forward to your further reply; with your help and more detailed information we can work together to find a solution. Thank you for your support and understanding.
Best Regards,
Kiki.Z - MSFT | Microsoft Community Support Specialist