Subject: Issue with Expired Certificate Error on HP Printer Using MacBook

[EJKrane · Accepted solution]

Easy and fast solution:

1 Open your printer's webpage.  If the MAC gives you an insecure web page error message, click through it.

2 Click on the Networking tab at the top of the window:

3 In the left hand menu, choose Certificates under Security

4 Choose Configure under the Installed heading

5 Create a New Self-Signed Certificate (first option). Click Next

6 Click Edit next to the last variable, Validity Period

7 In the blank box next to Validity Period, type in 3650. Click Apply.

8 Have a cup of coffee.  By the time you're done the new certificate will be installed.

9 Forget about doing it again for the next 10 years.

[gadgetguy]

Except you missed the part where this did not fix things for many people, including myself.

The "full" fix including time sync issue was posted earlier in the thread. If your Printers time gets out of sync with your host PC this can cause the certificate error.

See here