When there is a client field that no longer exists in MSCRM (e.g.: client_conversicahotlead) but is still a mapped field in PSS (kore_attributemapping). The error is preventing the sync to pull the updates from MSCRM to PSS. 

Resolution is to deactivate the kore_attributemapping record of client_conversicahotlead and resync the Contact (via Manual Data Sync (By Id)).