Symptoms
When creating a new workflow using the SharePoint Process template in K2 Studio and integrating with SharePoint 2013, K2 cannot find the SharePoint site. When manually entered, K2 Studio cannot find lists/libraries or other elements for integration.
<img src="http://community.k2.com/t5/image/serverpage/image-id/1773i889C9C213A3ABCAC">
Diagnoses
When creating a new workflow in this manner, K2 uses the SharePoint 2010 integration wizards.
Resolution
In order to integrate with SharePoint 2013, select "Blank Process" instead of "SharePoint", and then drag the appropriate SharePoint 2013 wizard into the workflow.