Content low error message

I am getting these errors. This is the output with -vvv. Would really be helpful the variable that is not defined was identified.

Anybody have idea how to debug this?

(ansible 2.2.RC3)

TASK [setup] ******************************************************************* fatal: [10.0.16.156]: FAILED! => {"failed": true, "msg": "Mandatory variable not defined."} fatal: [10.0.17.136]: FAILED! => {"failed": true, "msg": "Mandatory variable not defined."} fatal: [10.0.16.224]: FAILED! => {"failed": true, "msg": "Mandatory variable not defined."} fatal: [10.0.17.60]: FAILED! => {"failed": true, "msg": "Mandatory variable not defined."} fatal: [10.0.19.137]: FAILED! => {"failed": true, "msg": "Mandatory variable not defined."}

Ok, this is only with 2.2.RC3. No error with 2.1.0.0.