California has made subtle changes to that Cal Civ Code section we all know and love. Be sure the language you include in your settlement agreement cites the new language.
Effective January 1, 2019, Section 1542 now reads:
A general release does not extend to claims that the creditor or releasing party does not know or suspect to exist in his or her favor at the time of executing the release and that, if known by him or her, would have materially affected his or her settlement with the debtor or released party.