Mandatory field "Involved Person" must be filled

Hi

Could you please guide us to fix this error.

When we try to assign Injured person or Witness (Report Incident or  Report Simplified Incident) it will show this error message. 

We are using EHSM CE 4.0. Configuration activity done correctly, we did compare it with Client 000.

We checked few SAP notes also, mainly note are applicable for CE 3.0.

Thanks

Sunil