Rendering Partials from another Folder

Hello Guys :slight_smile:
I'm fairly new to Rails and a problem keeps bugging me for days now.

I'mt Trying to render a Partial from my App/view/pins folder to my
app/view/layout folder (My menu).

Basically im trying to render my _form.html.erb to a Modal which is
triggered with a button on my Menu.

Im using Bootstrap.

Every time i give my modal the code:

<%= render 'pins/form' %>

i'm getting:
NoMethodError in Pins#index
undefined method `model_name' for NilClass:Class

I searched A LOT and EVERYWHERE but couldn't fix it..
Can anybody Help me?

(Git repo-> https://github.com/Theminijohn/Amphitryon)

The object youโ€™re using to render the form is nil.