Conversion operators cannot convert from a derived type
A conversion operator is declared with a parameter type that derives from the return type.
At compile time, Visual Basic considers a predefined conversion to exist from any reference type to any type in its inheritance hierarchy, that is, any type from which it derives or which derives from it. Such a conversion might fail at run time, but the compiler cannot predict run-time results, so it allows any such conversion to compile.
Because the compiler considers this conversion to be already defined, it does not allow you to redefine it.
Error ID: BC33031
To correct this error
Remove this operator definition entirely. It is already predefined.