Object reference not established to an occasion of an item. Description: An unhandled exception occurred over the execution of the present Website request. Please evaluate the stack trace For more info with regard to the error and exactly where it originated from the code.C? gi?i hóa là ho?t ??ng th? công c?a m?t công vi?c s? d?ng máy móc ???

Object reference not established to an instance of an item. Description: An unhandled exception happened over the execution of the current World-wide-web request. Please critique the stack trace To find out more with regard to the mistake and in which it originated during the code.Lo?i t? ??ng hóa này ???c s? d?ng ?? th?c Hello?n các ho?t ??ng c