Hi.

Pull off the bottom grill and locate the quick disconnect near the freezer door. Pull out the water line from the coupling and with both doors closed press the water lever at the dispenser.
If the water comes out of the line - you have the frozen tube inside the freezer door. In that case you need to defrost the fridge.
If there is no water - then the water reservoir inside the fresh food, behind the crisper drawer is frozen. Defrost it and adjust the temperature.

Thank you. Post the results.

Simon.