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="14E9E02C-4553-11F1-BC84-D773242F1D8B" encoding="&#x2713;">
    <field widget="text" value="" key="username" attrs="" id="uuid-14EA03B8-4553-11F1-BC84-D773242F1D8B" name="username" display="Username"/>
    <field widget="password" key="password" attrs="" id="uuid-14EA4C38-4553-11F1-BC84-D773242F1D8B" name="password" display="Password"/>
    <field attrs="" id="uuid-14EA9788-4553-11F1-BC84-D773242F1D8B" key="submit" value="" widget="submit" display="Login" name="submit"/>
  </form>
</response>