I downloaded F2C Metadata Injector plugin from here and installed it in my Joomla 3.6.0 running a blank Template.
I created the metadata_injector_contenttype_XX.tpl and replaced XX by 2, which is the ID of my F2C Content Type and filled it with <pre class="line-numbers"><code class="language-markup"><m-eta property="og:title" content="{$JOOMLA_TITLE}" /></code></pre>.
So far - so good... easy.
The moment I activate the Plugin, every article with the content type 2 (as described) stops working for no reason. I did not even refresh any article.
I get a 1054 Error. This is it.

I reinstalled the plugin but it did not help. Other F2C stuff that is running: Form2Content Metadata Generator, Form2Content SEF, Form2Content Pro, Form2Content Search
Thank you for your support!

best regards, Wanja