Why does your GFCI trip when you plug in the refrigerator?

A GFCI trips whenever it senses a grounding problem. Not grounding the outside surface of radiOS, fans, fridges, metal lamps and hand tools can put 120 volts on the device where you can touch it and possibly be killed.

The GFCI trips so you will not be killed. Best to have an electrician check out your fridge. If it is OK, then the GFCI may be At Fault.