I have had the same problem intermittently.
Pulled the fridge out to check the water solenoid, worked fine.
Checked the section of line from the dispenser to the water pipe connection under the lower kick panel with compressed air - all fine there no blockage or freezing of the line.
Turns out that the water chiller tank located behind the second shelf from the bottom was frozen.
My solution was to take a hair dryer to it for a few seconds - worked just fine.