I have a problem that cannot extend the template website.contactus. It throws error

ValueError: Element '<xpath expr="//div[@name='mail_button']">' cannot be located in parent view

The view is in the table ir_ui_view and it has a div called mail_button. I've tried to extend it like it's extended by the website_crm addon. But the wierd thing is that there is no template with the id contactus in the website addons folder.
The confusing thin is that this worked, bud then I added something to my custom template and upgraded my custom module and it stopped working. I remember that I could there was an option to show this template in the website Customization menu but when you clicked on it the option vanished. I suspect that this is the problem.

How can I get the contactus page back? Or how do I fix the error?