RDLC If expression return #Error when data available

Hi Guys, 

my RDLC expression return #Error when data available,

when no data i got "Never Register" but when data available i got #error ?

please tell me whats wrong with my expression ?

=IIF(First(Fields!regisration_date.Value, "dataset_registration") = "", "Never Register", First(Fields!regisration_date.Value, "dataset_registration"))

Thankyou & Best Regards,
Wibowo Wiwit.