@witter1, Eric, I do not own this printer, did a search on the issue you are having and found these troubleshooting links below that may help solve your printers issue of out of paper. Good luck. I hope this helped you out, if so let me know by pressing the helpful button.
https://h30434.www3.hp.com/t5/Inkjet-Printing/OfficeJet-8600-reports-out-of-paper-but-there-is-paper-in/td-p/1479721
https://support.hp.com/us-en/document/c02920174
https://h30434.www3.hp.com/t5/Inkjet-Printing/out-of-paper-message-hp-officejet-pro-8600/td-p/1259975
https://answers.microsoft.com/en-us/windows/forum/windows_vista-hardware/out-of-paper-error-when-there-is-paper/0c6df644-8661-4515-9fde-163a8e2a69be