Can't set up printer because embedded web server can't communicate

[Grag]

Nasty problem with a new printer and a badly thought-out and even worse documented setup process. I'm posting to give a couple of workaround hints and also in the hope that someone from HP will spot this and fix the documentation and the design issues for future products.

Very obscure from the documentation but a phone conversation with HP Support revealed that what I needed to do to set up my printer was to use a browser to connect to its embedded web server. The recommendation was to connect by entering its IP address into the browser address bar. Quite tricky at that point to find the IP address because the printer itself was unresponsive; that's disappointing, but not the point if this post.

What went wrong was that the printer's web server refused to do anything useful until it had switched to using https and that's the communication that doesn't work. I found two issues: first, like any web server supporting https it has to provide a security certificate. The certificate it provides is "self-signed" and therefore not automatically trusted by any competent web browser. If you ignore its scary messages and tell the browser to trust the certificate anyway you hit the second issue. What a server certificate really does is to assure your browser that the server really owns the domain name the browser is accessing. When, as HP support recommended, you use the IP address it never matches the certified domain name and the browser complains again. In the case of an up to date MacOS Safari it simply refuses to connect and the printer remains unusable.

Workaround #1: I got it going by using Firefox, which also gave warnings, but allowed me to override it.

Workaround #2: When the web server warns about security select the option to view the certificate. Note the "Common Name" given by the certificate. Mine has the format HP999999 (where the 9s represent different digits). Safari displays this name at the top of its certificate pop-up. Now put that name in the address bar of your browser instead of the IP address. You may still get a security warning because the certificate is self-signed, but Safari now accepts your override and lets you proceed.