Error while intergrating with K2

Hello,

I get an error while trying to intergrate UiPath with K2. I laucnhed wizrad on ‘Start K2 Workflow’ activity. Then I filled all required field. After I select my test workflow from the the Workflows list, I get an error message “Selected workflow has validation errors, please select a different workflow.” BTW, the test workflow in K2 is OK, i tested it.

Can anyone help please?
Thanks