Page_Validators is undefined [Solved] in ASP.NET 4.5 – RadScheduler

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Earlier this week, I used the ASP.NET AJAX RadScheduler for the first time. Once I set the necessary properties and tried to debug the page on which the RadScheduler (version 2014.2.618.45) control resided, even though I was performing no binding at all yet, I received the following error:

Page_Validators is undefined

After some research, I discovered that client-side validators work differently in ASP.NET 4.5. Microsoft’s methodology utilizes jQuery and when using a RadScriptManager you can encounter difficulties. The expectation is that you will have jQuery in the global jQuery variable, but Telerik provides it via the $telerik field.


Short of registering my own jQuery on the page to get around this, I decided to simply disable the UnobtrusiveValidationMode by adding the following key to my <appSettings> section:

<add key=”ValidationSettings:UnobtrusiveValidationMode” value=”None”/>