In this case, it seems the hash browns did not turn out well.
For further precision, "misfire" doesn't always mean that something was executed badly.
Ex: “Since I was already serving waffles and biscuits, I think the hash browns were a bit of a misfire. The meal was too heavy on carbs.” In this case the hash browns weren’t necessarily prepared badly, but it was a bad idea to make hash browns in the first place.
In general "misfire" means the desired result was not achieved.