Answered Error messages in Register don't work

[[!Register?
    &submitVar=`registerbtn`   
    &preHooks=`formatDob`
    &activationEmailTpl=`myActivationEmailTpl`
    &activationEmailSubject=`Please activate your account in Test Forum!`
    &activationResourceId=`9`
    &submittedResourceId=`13`
    &usergroups=`19`
    &useExtended=`1` 
    &excludeExtended=`email:required:email,login-updprof-btn`
    &validate=`nospam:blank,
  username:required:minLength=^6^,
  password:required:minLength=^6^,
  password_confirm:password_confirm=^password^,
  fullname:required,
  email:required:email,
  date_of_birth:required,
    &placeholderPrefix=`reg.`
]]
<h1>Register</h1>
<legend class="loginFPLegend">Required Fields</legend>
<div class="register">
    <div class="registerMessage">[[!+reg.error.message]]</div>
        
    <form class="form" enctype="multipart/form-data" action="[[~[[*id]]]]" method="post">
        <input type="hidden" name="nospam" value="[[!+reg.nospam]]" />
        <!--Username-->
<li style="border-bottom:1px dashed #7e7e7e;"><label for="username">[[%register.username? &namespace=`login` &topic=`register`]]
            <span class="error">[[!+reg.error.username]]</span>
        </label>
        <input type="text" name="username" id="username" value="[[!+reg.username]]" />
<p class="note">Minimum 6 characters, and at least one letter.</p></li>
        <!--Fullname-->
        <br class="clear" />
<li style="border-bottom:1px dashed #7e7e7e;"><label for="fullname">[[%register.fullname]]
            <span class="error">[[!+reg.error.fullname]]</span>
        </label>
        <input type="text" name="fullname" id="fullname" value="[[!+reg.fullname]]" />
<p class="note">Whatever name you prefer. In the forums you may use a display name as well.</p></li>
        <br class="clear" />        
<!--Password-->
<li style="border-bottom:1px dashed #7e7e7e;"><label for="password">[[%register.password]]
            <span class="error">[[!+reg.error.password]]</span>
        </label>
        <input type="password" name="password" id="password" value="[[!+reg.password]]" />
     
        <label for="password_confirm"> Confirm
            <span class="error">[[!+reg.error.password_confirm]]</span>
        </label>
        <input type="password" name="password_confirm" id="password_confirm" value="[[!+reg.password_confirm]]" />
<p class="note">Minimum 6 characters.</p></li>
        <!--Email-->
        <br class="clear" />  
<li style="border-bottom:1px dashed #7e7e7e;"><label for="email">[[%register.email]]
            <span class="error">[[!+reg.error.email]]</span>
        </label>
       <input type="text" name="email" id="email" value="[[!+reg.email]]" />
<p class="note">Must be a valid email.</p></li>
        <br class="clear" />
        <!--Date of birth If you want it in the User General Information field than "date_of_birth" must be replaced with "dob"-->
<li style="border-bottom:1px dashed #7e7e7e;"><label for="date_of_birth">Date of Birth:</label>
            <span class="error">[[!+reg.error.date_of_birth]]</span>
        </label>
        <input type="text" name="date_of_birth" id="dob" value="[[!+date_of_birth:date=`%Y-%m-%d`]]" />
<p class="note"><b>Must</b> be in the form YYYY-MM-DD! DoB is only for verification purposes.</p></li>
        <br class="clear" />
        <div class="form-buttons">
            <input type="submit" name="registerbtn" value="Register" />
        </div>
        <br class="clear" />
    </form>
</div>