The compiler was parsing (“counting”) the arguments (keys) for the key map one by one. Since the compiler doesn’t care what they are named, how they are formatted in your sketch, or in what order you define them, it just expects there to be 64 keys and that’s it. However, after the ShiftToLayer(FUNCTION), which was the 62th argument, the keys abrubtly stopped.
The reason why ShiftToLayer(Function) is pointed out by the compiler is because that’s where it expected the last 2 keys to be, but there were none.