Why is Craft rendering a blank page instead of an error template? I'm currently seeing this in the PHP error logs:


Fatal error: Uncaught exception 'Craft\\HttpException' with message '' in
/home/vagrant/htdocs/site/craft/app/controllers/TemplatesController.php:59\nStack
trace:\n#0 (): Craft\\TemplatesController-&gt;actionRender()\n#1
/home/vagrant/htdocs/site/craft/app/framework/web/actions/CAction.php(109):
ReflectionMethod-&gt;invokeArgs()\n#2
/home/vagrant/htdocs/site/craft/app/framework/web/actions/CInlineAction.php(47):
CAction-&gt;runWithParamsInternal()\n#3
/home/vagrant/htdocs/site/craft/app/framework/web/CController.php(308):
CInlineAction-&gt;runWithParams()\n#4
/home/vagrant/htdocs/site/craft/app/framework/web/CController.php(286):
CController-&gt;runAction()\n#5
/home/vagrant/htdocs/site/craft/app/framework/web/CController.php(265):
CController-&gt;runActionWithFilters()\n#6
/home/vagrant/htdocs/site/craft/app/framework/web/CWebApplication.php(284):
CController-&gt;run()\n#7
/home/vagrant/htdocs/site/craft/app/framework/web/CWebApplication.php(141):
CWebApplication-&gt;runController()\n#8
/home/vagrant/htdocs/site/craft/app/etc/web/WebApp.php(288):
CWebApplication-&gt;processRequest()\n#9
/home/vagrant/htdocs/site/craft/app/framework/base/CApplication.php(185):
Craft\\WebApp-&gt;processRequest()\n#10
/home/vagrant/htdocs/site/craft/app/index.php(62):
CApplication-&gt;run()\n#11
/home/vagrant/htdocs/site/public/index.php(19): include()\n#12 {main}



I have a _404.html template under templates/ and the errorTemplatePrefix set to _.
Turns out it was HHVM causing the issue. Switching back to 'normal' PHP made the problem disappear.