Hi there, @EE.
There are some cases in which the system will not continue uploading attachments because it is not supported. This is to protect the security of your QuickBooks account. The following file types are supported for attachments: PDF, JPEG, PNG, DOC, XLSX, CSV, TIFF, GIF, and XML.
Furthermore, it can't contain special characters in the file name. You can check out this article to learn about special characters: Acceptable characters in QuickBooks Online.
After checking it, we can also try uploading your attachments using a private browser. Often, stored history in a regular browser can cause unexpected errors in the program.
You can use these keyboard shortcuts:
- Google Chrome: press Ctrl + Shift + N
- Mozilla Firefox: press Ctrl + Shift + P
- Safari: press Command + Shift + N
Once signed in, try uploading the attachments, if it is working. I'd recommend clearing your browser's cache; you can check the link clear cache and cookies to fix issues when using QuickBooks Online to refresh the website preferences that might have caused the issue.
You can also use other supported engines to check what computer and browser are suitable to better experience QuickBooks.
Can we also request a screenshot of the exact error message that appears, if there's any? for us to identify the exact error you've encountered?
You might want to learn about transactions that support attachments, you can read through this article: Add or delete attachments in QuickBooks Online.
Feel free to reply to this post, if you have further clarifications with attachments. Keep safe.
