By freezing, do you mean ice is forming on the cold plate? If so, it's a common problem and all you can do is defrost the system occasionally.
50F is very good for ales.
Remember one unassailable statistic, as explained by the late, great George Carlin: "Just think of how stupid the average person is, and then realize half of them are even stupider!"
"I would like to die on Mars, just not on impact." Elon Musk