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" uri="" key="login" uuid="94B2D22A-92B3-11F1-8568-CF39400CC38E" encoding="&#x2713;">
    <field value="" key="username" name="username" attrs="" display="Username" widget="text" id="uuid-94B305CE-92B3-11F1-8568-CF39400CC38E"/>
    <field key="password" attrs="" name="password" display="Password" id="uuid-94B353B2-92B3-11F1-8568-CF39400CC38E" widget="password"/>
    <field display="Login" widget="submit" id="uuid-94B39DE0-92B3-11F1-8568-CF39400CC38E" value="" key="submit" attrs="" name="submit"/>
  </form>
</response>