California Codes, Code of Civil Procedure - CCP, Part 2 — Of Civil Actions, Title 6 — Of the Pleadings in Civil Actions, Chapter 3 — Objections to Pleadings; Denials and Defenses, Article 1 — Objections to Pleadings, Section 430.80
(a) If the party against whom a complaint or cross-complaint has been filed fails to object to the pleading, either by demurrer or answer, that party is deemed to have waived the objection unless it is an objection that the court has no jurisdiction of the subject of the cause of action alleged in the pleading or an objection that the pleading does not state facts sufficient to constitute a cause of action.
(b) If the party against whom an answer has been filed fails to demur thereto, that party is deemed to have waived the objection unless it is an objection that the answer does not state facts sufficient to constitute a defense.
Notes
Sets waiver rules for pleading objections not timely raised: objections to a complaint or cross-complaint are generally waived if omitted from demurrer or answer, except subject-matter jurisdiction and failure to state a cause of action. Objections to an answer are generally waived without demurrer, except failure to state facts sufficient for a defense.
Use as reference
Lexinter.net | California Code, Code of Civil Procedure - CCP § 430.80 | https://laws.lexinter.net/codes/california/code-of-civil-procedure/part-2/title-6/chapter-3/article-1/section-430-80