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

Have you experienced this problem when you browsed your website or web application using Visual Studio 2013 or 2015?

A simple solution to this issue is to add something like the one below on your web.config file:

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