Most probably the button postback is not happening because of a validation control on the page, containing the RadButton. There are certain cases in which the validation requirements are not met and the RadButton
doesn’t initiate postback, which may cause confusion if the validation
is not easy to spot and the button is not supposed to be part of it.
If you want to exclude the RadButton from the validation mechanism of the page, you can set its CausesValidation
property to false (this is also valid for a regular asp Button control).