Symptoms

'Data at the root level is invalid' - when using SmartObject call
 

Diagnoses

I've spent hours today trying to figure this one out and I now realize I need your help.

I have a simple workflow that does a SmartObject call to two different lists (Policies, and Processes) to get the document ID based on a certain filter. From the Policy list I can get 1 item back. But if I try to get 2,3 or 4 items back I get the 'Data at the root level is invalid' error. As soon as I remove the items back to 1, it works fine. I have the exact same configuration for the Process library and there it works just fine to get 1, 2 or 3 items. I've removed the events in K2 Studio and rebuilt the Policy events to look exactly like Process but it keeps failing.
 

Resolution

This was recognized as a bug with the CSOM broker in 4.6.8 when a type 'HyperLink' is involve. Customer upgraded to 4.6.9 in which the fix was included to resolve this issue.