URI is not registered (Settings | Languages & Frameworks | Schemas and DTDs) in applicationContext.xml

I created an application Context.xml at the WEB-INF/classes directory. and I have added the <!DOCTYPE> in the xml. I am getting the below error:

URI is not registered (Settings | Languages & Frameworks | Schemas and DTDs)

You can see the snapshot below:

The xml is below:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE beans PUBLIC "-//SPRING//DTD BEAN//EN" "http://www.springframework.org/dtd/spring-beans.dtd">  // -> there comes the issue
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd">

</beans>