Why am I getting an error message when I try to retrieve pdf's that I have uploaded and attached to Vendor transactions? Error is invalid authorization ?

Welcome to the Community, Guyer. Allow me to share a troubleshooting step that may solve this issue.

Let's start by opening an incognito or private browser window. You can use the following keyboard shortcuts for the most popular browsers: 

• Google Chrome: Ctrl + Shift + N
• Mozilla Firefox: Ctrl + Shift + P
• Microsoft Edge: Ctrl + Shift + P
• Safari: Command + Shift + N

Once you have opened the browser window, log in to your QuickBooks account and retrieve the PDF again. If it's successful, proceed to clear your browser's cache. This process removes and fixes specific issues and helps the program run flawlessly. Additionally, you can use other devices and supported browsers to ensure everything works as expected.

Furthermore, ensure that your Adobe Acrobat is up to date.

Additionally, you can run a report with vendor totals to see how much you've paid them.

Let me know if you need further assistance in retrieving your files in QBO. I'm here to help in any way I can. Have a great day!