Do your other gas appliances work? If they don't, you have a gas supply problem like a regulator. If they work, it's the fridge itself with the problem. If you go outside and remove the bottom panel behind the fridge, you will see the burner tube, igniter etc. While someone inside manipulates the controls, observe the end of the burner tube. You should hear a sparking, and if everything works well, a gas flame will appear shortly afterward.

If there is no sparking, the ignition circuit needs to be attended to, If there is a spark and no flame, it is a gas problem. The gas system has a few components, a thermocouple, thermostat, burner tube and orifice. If the gas is plugged at any point, you'll have no flame.

While you're looking around, check all the wires to see that they are in place. If the wire to the solenoid has come loose, the gas valve will not open. If the wire is off the ignitor, there will be no spark. Just look around and see that all is intact.

If there is no simple fix, your dealer and warranty are the best options.

Gard

Is it one of the 3.0 fridges?  I have one and through trial and error have found the best way to get it to light.

turn the propane on and wait at least 10 minutes.  Then try to light the fridge.  I don't remember the technical terms, but you push in and hold the one button, and the quickly hit the stricker, holding the other button down.  If the red line starts to move, continue to hold the one button down until it reaches the far side.  Then you can let the button up and watch to make sure it doesn't slide backwards.

If the red line doesn't move, stop and wait about 2-3 minutes more.  I found it takes awhile for the propane to get in the lines.  If I try to soon nothing happens, if I wait it starts right up.

Probablly got some spider webs in orifice. Also I find mine easier to light if I get the gas flowing to something else 1st (like hot water heater)

I Second Rocyrider, If I haven't run the appliance in a while, the hot water heater will start faster. I start that first and then the fridge will start by the third try. I hope this is your simple problem!

Are your batteries charged? If you are not plugged in and your batteries are low your ref. will not run on LP. Also if you are plugged in and you have your ref on auto it will automaticly go to AC and not LP. 

Good Luck