You receive an error when attempting to sync if you have changed the Format of a Line Item to Number and enabled Breakback on that same Line Item, within the same revision.
An internal error occurred while preparing the structural changes for synchronization. Reason for error: Line item M.a does not currently support Breakback.
To work around this, disable breakback for the Line Item referenced in the error, sync to your production model, enable breakback for the same Line Item, sync to your production model.
If this workaround is not suitable in your use case, please contact our Care team.