Symptoms
On a site collection within SharePoint site branding has been applied. After this has been done, SmartForms will not render on any SharePoint pages once a list has been Appified.
Diagnosis
Add Appit functionality to a list and select Forms. This will autogenerate the New, Display, and Edit forms for the list. Now, from the list, these forms can be exposed by either clicking to add a new item to the list, or clicking on an existing item in the list to see the item displayed in the "Display List" SmartForm.
Once site branding is applied to the same site collection in question, navigating to the specific pages that normally surface the New, Edit, and Display SmartForms will render either a blank page or a loading spinner that will spin indenfinately.
Disabling site branding on the site will allow SmartForms to render correctly again.
Solution
This is a known issue with Appit ver.4.6.8. If you are having this issue with SmartForms not render after site branding has been applied to a site collection in your SharePoint environment, please visit portal.k2.com and log a support ticket describing that you are having this issue. A member of our Appit support team will evaluate your SharePoint environment to see if a temporary fix can be applied to resolve the issue.
Our Appit development team is aware of this issue and is working to implement a permanent fix to this problem in a future update of Appit.