0050: Not enough parameters for command
It may happen if fewer parameters are provided or some of them are invalid. The number of parameters for each built-in command is hardcoded and can't be changed. The number of parameters in the class corresponds to the underlying opcode configuration.
Possible solutions: provide the required number of parameters:
{$INCLUDE} // error, one parameter missing
Player.Defined() // error, one parameter missing
INC() // error, expected two parameters
{$INCLUDE file.txt} // OK
Player.Defined($PLAYER_CHAR) // OK
INC($var) // OK