ASP.NET Custom Validator Client side & Server Side validation not firing

Question

This has not happened to me before, but for some reason both the client and server side validation events are not being triggered:

Answer 1

Server-side validation won't fire if client-side validation is invalid, the postback is not send.

Don't you have some other validation that doesn't pass?

The client-side validation is not executed because you specified ClientValidationFunction="TextBoxDTownCityClient" and this will look for a function named TextBoxDTownCityClient as validation function, but the function name should be TextBoxDAddress1Client

(as you wrote)