Is the TT level? If you had it on AUTO, the fridge would use AC voltage when it was present. If you unplugged the shore power, the fridge should light on propane. If it fails to light on propane, it will give the flashing light error. I usually purge my gas by turning on a few stove burners for about 10 seconds but the fridge still may take a few tries to light.
You could have also tripped a safety valve in the propane tank if you opened the tank valve too fast. If your gas pressure is low at the stove burners, shut the tank off, open a stove burner for a minute or so to relieve the residual pressure in the lines. Close the stove burner then open the tank valve slowly and see if the propane is back to normal pressure.
2013 26BH ghetto model w/ 4 plain rims and some rust
2001 Silverado 2500HD 6.0 gasser
I have a fever...and the only cure is more camping!