I have gone through the troublehsooting steps in your FAQ. (activating a stock theme, disabling plugins, etc)
I have Button Type – Image is pre-selected checked as well as Disable pinit.js (as nothing works if I don’t have that selected).
I’m using a modified Rustik theme with Woocommerce enabled.
Clicking the button takes me to the Pin screen as expected. The description is filled out correctly, however, no image shows up, nor can I select one. I get this error:
“You need to upload an image or provide the ‘image_url’ parameter”