Beer won't pour - unless keg on its side - RESOLVED!!!

Help.  I am new to the world of kegerator, not to drinking beer.  Got everything hooked up, CO2, 1/2 barrel of Stone IPA, Friday night, no work for the next 2 days.  Nothing.  Pull the handle and nothing put spitting and just a little foam.  Pressure is at 12%…lines are new and clean…nothing…pull the keg out, lay it on its side…PERFECT!  What the heck???  It’s a good workout to pull the keg out, place it on its side, pour a beer, replace, drink, repeat.  But?  What is going on?

RESOLVED!!

***********  THANKS! *************

My first thought is that the connectors are hooked up backwards.  The ‘OUT’ line has a dip tube that goes to nearly the bottom and draws out from the bottom, the ‘In’ line dip tube only extends an inch or so, allowing the CO2 to pressurize from the top.  If it only pours when keg is on it’s side then I’m thinking that’s because beer is reaching that ‘in’ dip tube…

Thanks.  I will reconnect the tap.  “No Assembly Required” so I just ASS-umed it was put together properly at the factory.  I will let you know.

If the beer was dry hopped some hop debris could be plugging the inlet of your dip tube.