Hey There, I am Anna Carter. HP printer offline error is a very common problem encountered by HP printer users. If your HP printer is offline, all you need is to upgrade the printer drivers. There are chances that you are using the outdated version of printer drivers, so update them now. After that, restart the print spooler service and set your printer as the default printing device to print the documents. Once you do this, the error will be resolved. And if not, run the printer troubleshooter to find and fix the issue automatically.