asp.net Button OnClick event not firing

Because your button is in control it could be that there is a validation from another control that don't allow the button to submit. The result in my case was to add CausesValidation property to the button:

<asp:Button ID="btn_QuaSave" runat="server" Text="SAVE" OnClick="btn_QuaSave_Click" CausesValidation="False"/> 

Have you copied this method from other page/application ? if yes then it will not work, So you need to delete the event and event name assigned to the button then go to design and go to button even properties go to onClick event double click next to it, it will generate event and it automatically assigns event name to the button. this should work

If you are using updatepanel on onclick event, this may happen.

Use 'EnableEventValidation="false"' in your page markup like this :

<%@ Page Language="C#" MasterPageFile="~/ars_home.master" AutoEventWireup="true" CodeFile="Transaction_Window.aspx.cs" Inherits="Transaction_Window" EnableEventValidation="false" %>

Hope this helps

I had the same problem, my aspnet button's click was not firing. It turns out that some where on other part of the page has an input with html "required" attribute on.

This might be sound strange, but once I remove the required attribute, the button just works normally.

In my case I put required="required" inside CKEditor control.
Removing this attribute fixed the issue.
Before

<CKEditor:CKEditorControl ID="txtDescription" BasePath="/ckeditor/" runat="server" required="required"></CKEditor:CKEditorControl>

After

<CKEditor:CKEditorControl ID="txtDescription" BasePath="/ckeditor/" runat="server"></CKEditor:CKEditorControl>