The first thing to do is make sure all the cables are connected securely to the printer and the PC.  Be sure to note if one of the cables is a network cable.  If all of the cables are securely connected and you still cannot print, restart the PC and the printer.  
If you receive the same error once the printer and PC are back up, there is likely a hardware issue with the printer.  If one of the cables that plugs into the printer is a network cable then the Jet Direct card (a network interface adapter for the printer) must be investigated. 
To verify the status of the Jet Direct card, print out the configuration of the printer.  To do this simply press and release the 'GO' and 'CANCEL JOB' button simultaneously.  If two pages print out then the Jet Direct is being detected properly.  At this point look at the second page and verify the settings are correct for your network. 
If only one page prints then the printer is not properly detecting the Jet Direct card.  If the card is not detected, power off the printer and reseat the card.  Once the card is reseated, power the printer on and print out the configuration. 
If the card is still not detected a 'cold reset' is necessary.  A cold reset will restore all of the settings within the printer to factory defaults.  Doing this can clear any corruption that may have occurred inside the printer or the Jet Direct.  To perform a cold reset use the following simple steps:
1.  Turn the printer power off.
2.  Press and hold GO.
3.  Turn the printer power back on and continue to hold GO until the Attention light turns on.
4.  Release GO.
5.  The device lights will begin cycling from front to rear.  The cold-reset process will run until completion and the device will go to the ready state.
After the cold reset, print a configuration sheet.  If the Jet Direct still does not show up, then the Jet Direct unit is bad and should be replaced.