Velocity can't find resource

Something is wrong and it is very frustrating. I read on velocity's homepage that when I run a webapp then some properties should be set. And I've done that but no matter what I do I keep getting the same error.
This is where I set the props and use velocity

public class ConfirmationMailGenerator implements MailGenerator {

    private BasicUser user;
    private String htmlTemplate = "HTMLConfirmationMailTemplate.vsl";
    private String plainTemplate = "PlainConfirmationMailTemplate.vsl";

    public ConfirmationMailGenerator(BasicUser user) {
        this.user = user;
    }

    public StringWriter generateHTML() throws Exception {
        Properties props = new Properties();
        props.setProperty("resource.loader", "wepapp");
        props.setProperty("webapp.resource.loader.class", "org.apache.velocity.tools.view.WebappResourceLoader");
        props.setProperty("webapp.resource.loader.path", "/WEB-INF/mailtemplates/");
        VelocityEngine engine = new VelocityEngine(props);
        VelocityContext context = new VelocityContext();

        engine.init();

        Map map = createDataModel();
        context.put("user", map);

        Template template = engine.getTemplate(htmlTemplate);
        StringWriter writer = new StringWriter();
        template.merge(context, writer);

        return writer;
    }
...
}

The files is of course saved in /WEB-INF/mailtemplates/.
If I use this I get this error:

SEVERE: ResourceManager : unable to find resource 'HTMLConfirmationMailTemplate.vsl' in any resource loader.
SEVERE: The log message is null.

Thank you for your time:)