Symptoms

Form not rendering on SharePoint site.
 

Diagnoses

Asked client for screenshots of the following ensure both .ccs file and folder were present in the Theme directory:
Your Install DriveProgram Files (x86)K2 blackpearlK2 smartforms DesignerStylesThemes

and

Your install driveProgram Files (x86)K2 blackpearlK2 smartforms RuntimeStylesThemes
 

Resolution

Client indicated the Runtime folder did not have the .CSS file or the folder. Client added them and issue was resolved.