Recently, I have been using ASP.NET Ajax in a project at job. If you have a Button inside an UpdatePanel, when you click it, you will sometimes receive an strange javascript error: ‘this._postBackSettings.async == null’. I have found that this can be solved with setting UseSubmitBehavior to false.
So everytime you have a Button inside an UpdatePanel, your buttons should be like this:
<asp:Button id="myButton" runat="server" UseSubmitBehavior="False" value="..." />
Happy hacking!
