XSLT Error

Empty filename at /home/ubuntu/perl5/perlbrew/perls/perl-5.18.0/lib/site_perl/5.18.0/Chameleon5/Template/XSLT.pm line 575.

Response XML

<?xml version="1.0"?>
<response>
  <form method="post" key="login" uri="" encoding="&#x2713;" uuid="FB6864B0-79A7-11F0-A67F-91C1F3489F51">
    <field name="username" widget="text" display="Username" id="uuid-FB68969C-79A7-11F0-A67F-91C1F3489F51" key="username" value="" attrs=""/>
    <field name="password" widget="password" display="Password" attrs="" id="uuid-FB68DDDC-79A7-11F0-A67F-91C1F3489F51" key="password"/>
    <field attrs="" value="" key="submit" id="uuid-FB692594-79A7-11F0-A67F-91C1F3489F51" display="Login" widget="submit" name="submit"/>
  </form>
</response>