问spring freemarker ConversionNotSupportedException

EN

<bean id="freemarkerConfiguration"
    class="org.springframework.ui.freemarker.FreeMarkerConfigurationFactoryBean">
    <property name="templateLoaderPath" value="/WEB-INF/templates" />
</bean>


<bean id="registrationMailService" class="com.epam.darts.webapp.utils.RegistrationMailService">
    <property name="configuration" ref="freemarkerConfiguration" />
    <property name="mailSender" ref="mailSender" />
</bean>

public class RegistrationMailService {

    private JavaMailSender mailSender;
    private Configuration configuration;

    public void sendConfirmationEmail(final User user) {
        MimeMessage message = this.mailSender.createMimeMessage();
        MimeMessageHelper helper = new MimeMessageHelper(message);
        try {
            helper.setFrom(user.getLogin());

            helper.setTo(user.getLogin());
            helper.setSubject(user.getLogin());

            Map<String, Object> model = new HashMap<String, Object>();
            model.put("user", user);

            String sendText = FreeMarkerTemplateUtils.processTemplateIntoString(
                        this.configuration.getTemplate("regisstration_mail.html"), model);
            helper.setText(sendText, true);
            this.mailSender.send(helper.getMimeMessage());
        }
        catch(MessagingException e) {
            e.printStackTrace();
           }
    }

    public void setMailSender(final JavaMailSender mailSender) {
        this.mailSender = mailSender;
    }
    public void setConfiguration(final Configuration configuration) {
        this.configuration = configuration;
    }
}

    <dependency>
        <groupId>freemarker</groupId>
        <artifactId>freemarker</artifactId>
        <version>2.3.9</version>
    </dependency>

 18:17:46,839 ERROR [ContextLoader] Context initialization failed
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'registrationMailService' defined in
ServletContext resource [/WEB-INF/spring/spring-mail.xml]: Initialization of bean failed; nested exception is org.springfram
ework.beans.ConversionNotSupportedException: Failed to convert property value of type 'freemarker.template.Configuration' to
 required type 'freemarker.template.Configuration' for property 'configuration'; nested exception is java.lang.IllegalStateE
xception: Cannot convert value of type [freemarker.template.Configuration] to required type [freemarker.template.Configurati
on] for property 'configuration': no matching editors or conversion strategy found