2978939 - Error "/CPD/SS_MESSAGES/416" occurs when using API /cpd/SC_PROJ_ENGMT_CREATE_UPD_SRV/A_EngmntProjRsceDmnd

Following error occurs when using API /cpd/SC_PROJ_ENGMT_CREATE_UPD_SRV/A_EngmntProjRsceDmnd to update the resource demand.
"/CPD/SS_MESSAGES/416"
Mismatch of employee and worker user ID in work package xxxxxx.x.x, demand yyyy.

SAP S/4HANA Cloud.

Execute API /cpd/SC_PROJ_ENGMT_CREATE_UPD_SRV/A_EngmntProjRsceDmnd to update resource demand. 

PersonWorkAgreement,WorkforcePersonUserID,Country2DigitISOCode,KeyDate in the payload are specified incorrectly.
Per on-line help,
If you wish to assign a person to the resource demand, you can do this in one of two ways:
1.Entering a value for PersonWorkAgreement
2.Entering a value for WorkforcePersonUserID, Country2DigitISOCode, and KeyDate

Please use one of the suggested two ways to update the resoure demand.
e.g. only enter a value for PersonWorkAgreement to update the resource demand.

/CPD/SS_MESSAGES/416, resource demand, Mismatch of employee and worker user ID in work package, A_EngmntProjRsceDmnd, SC_PROJ_ENGMT_CREATE_UPD_SRV , KBA , CA-CPD-SS , S/4HANA Professional Services Cloud - CPM , Problem