HP printers on WiFi are suddenly not printing from your Apple device? Read on...
Turns out that Apple has messed up WiFi printing for HP printers via one of their recent updates. The symptoms are that you can see the printer in your list but when you send a page to be printed it would not go though fore the timeout whilst attempting to connect to that printer. Similarly if you try to print from your Mac laptop or desktop and that simply not happening but you can scan (thus you know that the connection is working) then you may have this problem.
There is no fix for the moment but a weird workaround if you really HAVE to print there and then. Nope I'm not talking about USB as it is not a WiFi connection and USB links are not affected. Check your printer configuration for Web Services and allow EPrint. This will issue your printer with an email and then anything sent to that email will be printed directly via HP servers.