Using Form Field setTemplate crashes SilverStripe/Apache

<%- if @topic_view.topic.tags.present? %>
<%= t 'js.tagging.tags' %>: <%- @topic_view.topic.tags.each do |t| %> <%= t %> <%- end %>
<% end %>

SS4

When I create a new form field and use setTemplate() SilverStripe/Apache crashes

I have played around with all sorts of locations for my custom FormField_holder template and backslashes/forward slash in the path. But, if SS cannot find my template the field is rendered with the default and if it can find it SS crashes. I have also had SS throw an error that it cannot stat the template, but I cannot seem to reproduce this at time of writing.

Here is the code I am using to create the Form object.

$fields = FieldList::create(

	TextField::create('Name','Name')
	->setTemplate('Forms\\FormField_holder') // crashes site!!

	,EmailField::create('Email','Email')
	->setTemplate('Forms\\FormField_holder') // crashes site!!

	,TextareaField::create('Message','How can we help you?')

);

$actions = FieldList::create(
	FormAction::create('submit','Send Message')
);

$required = RequiredFields::create(
	'Name',
	'Email',
	'Message'
);

$form = Form::create(
	$this,
	__FUNCTION__,
	$fields,
	$actions,
	$required
);

And the contents of app\templates\Forms\FormField_holder.ss

<div class="field<% if $extraClass %> $extraClass<% end_if %>">
    <% if $Title %><label for="$ID">$Title</label><% end_if %>
    $Field
</div>

This is driving me up the wall, so I really hope someone can point me in the right direction!

Cheers,
Olly

Turns out you need to use setFieldHolderTemplate() when specifying a title in the creation argument list…