ENCRYPTION credentials expired - using a mac

[JANMARIETTA]

I get the error message that the encryption credentials have expired. The instructions from HP indicate steps to follow using Windows of PC. I have a Mac. When I try to follow the steps anyway I get a warning about a potential security risk. What to do?

[GM-2021]

I had the same problem.  None of the solutions I found from HP worked - the printer's web server page didn't look like the one they showed, menus were different, etc.   In the end, by wasting a whole bunch of time googling, the following worked for me:

I found security settings deep in the network settings menu on the printer (HP M553), and found a 'Reset security settings' option, which I did. 

I then shut down the printer, uninstalled it on my mac, restarted the printer, re-installed it on the mac, and selected 'Generic Postcript driver' (it offered Airprint but I don't use wireless connections).

The printer now works again.  Although the generic postcript driver doesn'e give all the device status info that the HP driver does, it does actually let me print, which is all I care about at this point.