Symptoms
After publishing an existing InfoPath solution. The SharePoint IP forms do not open correctly. It give the error attached. I think it has something to do with the K2 deployment not publishing the form correctly.
Diagnoses
Data Connections where not converted.
Resolution
Recreated the Infopath Data Connections, converted them to UDCX, and published the Data Connections to the K2 Blackpearl Data Connection library in Sharepoint. Changed the Version in SP to use the latest Infopath Version.
This resolved the issue