canon printer error: Printer Encryption Credentials Have Expired

Create a New Self-Signed Certificate for a TS9120

Open System Settings (System Preferences) > Printers & Scanners. Select the printer with the error by clicking it once. Look for “Options & Supplies…” and click that button. In the middle of the new window click “Show Printer Web Page…” The default web browser will open the printer’s HTTP (web) utility starting with a warning. “This Connection Is Not Private” for Safari; “Warning: Potential Security Risk Ahead” for Firefox; “Your connection is not private” for Google Chrome.

- In Safari click “Show Details.” Move the curser over the “visit this website” link to see the address in the Address Field at the top of the page: https://printername.local./rui/logon_manager.html?page=PAGE_AAP. Clicking that link will open a verification window, click “Visit Website.”

- In Firefox click “Advanced…” then “Accept the Risk and Continue”

- In Chrome click “Advanced…” then “Proceed to sivonenprinter.local. (unsafe)” This link is quite small at the bottom of the page.

Enter the administrator password and click “OK” at the bottom of the page, or click “About password and cookies.” If you don’t have a password or don’t know it follow the Canon manual instructions. 

Canon’s Remote User Interface support site: https://support.usa.canon.com/kb/index?page=content&id=ART167430.

The AirPrint Settings menu opened by default for me. Click on “Security” then click on “SSL/TLS settings”. There are four choices presented: Generate, Upload, Delete, and Check. Generate key and certificate is very likely what you want to pick. Home users will then likely want to “Generate self-signed cert.”

The default “SHA256” is lower encryption level. I don’t believe selecting one of the higher levels affects the following steps. Enter values for the “Valid from”. The day before worked for me. Enter values for “Valid to.” I picked 2030. The “Common name” should not have any spaces. Clicking “Next” at the bottom of the page will move to the last entries for Country, State, Locality, Organization, and Unit. I used US; ME: City; Company/Family; and Room to fill these in.

If the printer queue with the expired certificate is still listed in Printers and Scanners, remove it and re-add the printer. It will have the new certificate now.

Boy, am I glad I administrate Apple devices for a living … I’m not sure if I could have gotten through these steps without understanding what a certificate was at the beginning. Canon definitely needed to use a later date for the certificate.