Hi Wyatt Boboltz,
Good day.
Thank you for posting to the Microsoft Community. We are glad to assist.
It sounds frustrating to encounter this issue. The error message you’re seeing is a known problem in the new version of Outlook. Here are a few steps you can try to resolve it:
Clear Temporary Files: Sometimes, Outlook saves attachments to a temporary folder, which can become full or corrupted. Clearing these files might help.
Update Outlook: Ensure that your Outlook is up to date. Sometimes, updates contain fixes for known issues.
Reconfigure Account: Try reconfiguring your email account in the new Outlook. This can sometimes resolve configuration issues12.
If these steps don’t work, you might want to switch back to the classic version of Outlook temporarily or use Outlook on the web, where attachments should open without issues.
If you’re still having trouble, you can try contacting Get support - Microsoft 365 admin | Microsoft Learn the support team will have access to assist remotely and collect logs to investigate the issue from the back end.
I hope this helps let me know if this is contrary to what you need, I would still be helpful to answer more of your questions .
Best Regards
Community Moderator