How to Fix WebForms UnobtrusiveValidationMode requires a ScriptResourceMapping for jquery Error in ASP.NET Web Forms

Introduction

While working with ASP.NET Web Forms, many developers face the following error:

WebForms UnobtrusiveValidationMode requires a ScriptResourceMapping for 'jquery'. Please add a ScriptResourceMapping named jquery (case-sensitive).

This error usually appears when:

• You create a new Web Forms project

• You update Visual Studio

• You use validation controls like RequiredFieldValidator

• jQuery is not properly configured

In this article, we will understand:

• Why this error occurs

• Where it occurs

• How to fix it step-by-step

• Alternative solution

• Best practice for beginners

Why This Error Occurs

ASP.NET Web Forms uses something called:

👉 Unobtrusive Validation

Unobtrusive validation depends on:

• jQuery

• jQuery Validation libraries

If jQuery is not registered properly in the project, this error appears.

When Does This Error Appear?

This error usually appears:

• When you run the project (F5)

• On pages that use validation controls like:

<asp:RequiredFieldValidator>

<asp:RegularExpressionValidator>

<asp:CompareValidator>

This is the simplest solution.

Step 1: Open Web.config File

Go to:

YourProject → Web.config

Step 2: Find <appSettings> Section

If it does not exist, add it.

Step 3: Add This Code Inside <appSettings>

<appSettings>

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

</appSettings>

Step 4: Save and Run Project Again

What This Code Does?

This line:

ValidationSettings:UnobtrusiveValidationMode = None

It disables unobtrusive validation.

So now:

• jQuery is no longer required

• Validation works using traditional method

• Error disappears