I suggest you run throught the smartforms setup manager and either Repair it, or go through the configuration and make sure your values are set appropriately. Also, make sure that reporting services are installed.

Hi Srikrishna

Please try to re-install the K2 for sharepoint app and the try to add the smartforms viewer app again. If the error still pops up try to create a subsite, install the k2 for sharepoint app on this subsite and then add the smartforms viewer app.

After you have tested this and the error still presists then navigate to I suggest that you rerun the k2 for sharepoint setup "C:
Program Files (x86)K2 blackpearlK2 for SharePoint 2013 SetupSetup.exe" after you have done this confirm that K2 for sharepoint app is still installed and try to add and use the smartforms viewer app again.

Kind Regards

Raymond