My sister's ex is reopening a case from 2006, where he was never awarded any CS. They sent paperwork in the mail apparently they've been trying to "locate her". They want her to fill out things about her income, etc... The prior case was closed where her and the other party got a notice stating the DSS closed the case. Because the case was closed by DSS should they serve her and should she acknowledge the receipt of these papers, or send them back? State is California. Thank You.