This is because in 5.2 constructor from uint16 to uint8 declared as deleted and your program dont know how to convert it. U have to use variable (FKey in this example) with type uint16 or uint32 and it will work
This is because in 5.2 constructor from uint16 to uint8 declared as deleted and your program dont know how to convert it. U have to use variable (FKey in this example) with type uint16 or uint32 and it will work