Reset Nintex Form for list

I am working on building a site template and have a Nintex form for one of my libraries. When I try to Edit an item, I get an error. So I tried to edit the form and when I click on the Nintex Form icon for the list, it opens Form Designer, but it just spins and doesn't open up. If I go into SharePoint Designer, I don't see Editform.aspx in Forms. 

Is there a way that I can remove the Nintex form customization without needing to go into Nintex Form Designer?

Thanks!

Chris