asp.net mvc - Fluent validation in Nop commerce - alphanumeric only -

asp.net mvc - Fluent validation in Nop commerce - alphanumeric only -

i'm trying create zip / postal code field in nop commerce 2.65 alphanumeric field. i've edited file addressvalidator.cs in nop.web admin folder next line:

rulefor(x => x.zippostalcode) .matches(@"^[0-9a-za-z ]+$") .withmessage("numbers , letters please.");

i've compiled , uploaded nopadmin.dll nothing, it's validation not there.

is code wrong or uploading wrong file?

i've tested code , works fine. presume forgot re-build nop.admin project 1 time modified. note solution has 2 "addressvalidator" classes. please ensure modified required one

asp.net-mvc nopcommerce fluentvalidation