K2 Activity

Hi, I created a very simple workflow in K2 - I am attempting to call this via the Start K2 workflow activity. I get an error "Selected workflow has validation errors-Select a different workflow" - But If I call the workflow using HTTP Request activity, I am able to call the K2 WF successfully - What could be the issue ? Any ideas ?

Thanks

I see I can set the data field values using the wizard. Is it possible to also set the other parameters accepted by the K2 workflow aip endpoint - for example "folio"? https://help.k2.com/onlinehelp/k2cloud/DevRef/current/default.htm#Runtime/WF-REST-API/Workflow-REST-API-Samples.htm