How can a Data Change Request be created without Data Change Request Lines?
Data Change Requests (DCRs) can be created without Data Change Request Lines (DCR Lines).
This can happen if there are Validation Rules present on the Data_Change_Request_vod__c and/or Data_Change_Request_Line_vod__c objects and a user submits a DCR with field values that fit the Error Condition Formula.
Validation Rules are unsupported on the Data_Change_Request_vod__c and/or Data_Change_Request_Line_vod__c objects. If present, when a user submits a new DCR for account creation, and field values do not validate, the account DCR, address DCR, and/or child account DCR are submitted. Then, the Validation Rule fires and the user has to correct the mistake in order to submit again. This can create DCRs without DCR Lines as well as duplicate DCRs with the appropriate DCR Lines.
To prevent this problem, remove the Validation Rules from the Data Change Request and/or Data Change Request Lines objects and place them on the appropriate account, address, and/or child account objects. Validation Rules on those objects should be respected when DCRs are submitted.
CRM Help Documentation: Offline Validation Rules