Little help needed with new template rendering in existing scripts

[Ted S]

I'm working on updating some existing mods (grumble) and have run into some confusion about getting templates to render on existing hooks.

Here's my simple render code. Any ideas why it isn't getting seen in postbit_legacy?

Plugin: showthread_postbit_create

$templater = vB_Template::create($helpful_answers_template);
 $template_hook[postbit_controls] .= $templater->render();

Thanks!