Symptoms

When first using the K2 App for a list or library in SharePoint 2013, when creating Smartobjects and Smartforms for New Item/Edit Item/Display Item, the forms are not showing up properly when the corresponding actions are chosen to view, edit or display an item. The iframe responsible for loading the form comes up empty.
 

Diagnoses

Regenerating forms and views does not do the trick. Removing and re-adding the K2 app from the site collection does not produce different results either. Therefore, it points to a SharePoint display issue.

 

Resolution

When assigning a site one of SharePoint 2013's built in themes, users have the option to choose which type of master page layout they would like to use. Choices are Oslo and Seattle. Utilizing the Oslo master pages will cause the forms on the site to not render for lists/libraries in the appropriate iframe, and after switching the master page type to Seattle, the forms displayed properly and as expected.