Login Exception when using JDBC Realm

<form action="j_security_check"  
              method="POST">  
            <table>  
                <tbody>  
                    <tr>  
                        <td>Username:</td>  
                        <td><input type="text" name="j_username"/></td>  
                    </tr>  
                    <tr>  
                        <td>Password</td>  
                        <td><input type="password" name="j_password"/></td>  
                    </tr>  
                    <tr>  
                        <td> </td>  
                        <td><input type="submit" value="Login"/></td>  
                    </tr>  
                </tbody>  
            </table>  
        </form>  

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="3.0" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee <a href="http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd">
" title="http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd">
">http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd">
</a>    <context-param>
        <param-name>javax.faces.PROJECT_STAGE</param-name>
        <param-value>Development</param-value>
    </context-param>
    <display-name>ProyectoSCN-web</display-name>
    <servlet>
        <servlet-name>Faces Servlet</servlet-name>
        <servlet-class>javax.faces.webapp.FacesServlet</servlet-class>
        <load-on-startup>1</load-on-startup>
    </servlet>
    <servlet-mapping>
        <servlet-name>Faces Servlet</servlet-name>
        <url-pattern>*.xhtml</url-pattern>
        <url-pattern>*.jsf</url-pattern>
        <url-pattern>/faces/*</url-pattern>
    </servlet-mapping>
    <session-config>
        <session-timeout>
            30
        </session-timeout>
    </session-config>
    <welcome-file-list>
        <welcome-file>faces/protected/admin/Instituciones.xhtml</welcome-file>
    </welcome-file-list>
   
    <!-- Protected Areas -->
    <security-constraint>
        <web-resource-collection>
            <web-resource-name>solo administradores</web-resource-name>
             
            <url-pattern>/faces/protected/admin/*</url-pattern>
            <http-method>GET</http-method>
            <http-method>POST</http-method>
        </web-resource-collection>
        <auth-constraint>
            <role-name>ADMIN</role-name>
        </auth-constraint>
    </security-constraint>
    <security-constraint>
        <web-resource-collection>
            <web-resource-name>solo docentes</web-resource-name>
           
            <url-pattern>/faces/protected/docentes/*</url-pattern>
            <http-method>GET</http-method>
            <http-method>POST</http-method>
        </web-resource-collection>
        <auth-constraint>
            <!--    <role-name>ADMIN</role-name>-->
            <role-name>DOCENTE</role-name>
        </auth-constraint>
    </security-constraint>
   
    <!-- Validation By Form -->
    <login-config>
        <auth-method>FORM</auth-method>
        <realm-name>jdbc-realm</realm-name>
        <form-login-config>
            <form-login-page>/faces/public/login.xhtml</form-login-page>
            <form-error-page>/faces/public/loginError.xhtml</form-error-page>
        </form-login-config>
    </login-config>
 
    <!-- Allowed Roles -->
    <security-role>
        <role-name>ADMIN</role-name>
    </security-role>
    <security-role>
        <role-name>DOCENTE</role-name>
    </security-role>
</web-app>

<glassfish-web-app error-url="">
    <parameter-encoding default-charset="UTF-8"/>

    <context-root>/ProyectoSCN-web</context-root>
 
 
  <security-role-mapping>
        <!-- ligar los roles de usuario definidos dentro del web.xml con los grupos definidos en el realm.-->
        <role-name>ADMIN</role-name>
        <group-name>ADMIN</group-name>
    </security-role-mapping>
    <security-role-mapping>
        <!-- ligar los roles de usuario definidos dentro del web.xml con los grupos definidos en el realm.-->
        <role-name>DOCENTE</role-name>
        <group-name>DOCENTE</group-name>
    </security-role-mapping>
    <class-loader delegate="true"/>
    <jsp-config>
    <property name="keepgenerated" value="true">
      <description>Keep a copy of the generated servlet class' java code.</description>
    </property>
  </jsp-config>
</glassfish-web-app>

Configuration Name: default-config
Realm Name: theRealm
Class Name: com.sun.enterprise.security.auth.realm.jdbc.JDBCRealm

JAAS Context: jdbcRealm
JNDI: jdbc/scn
User Table:v_usuario_roles
User Name Column: NOMBREUSUARIO
Password Column: password
Group Table: v_usuario_roles
Group Name Column: group_id
Assign Groups:
Database User:
Database Password:
Digest Algorithm:
Encoding:
Charset: