Any defense as to the sufficiency of the claim based upon a defect or omission in the claim as presented is waived by failure to give notice of insufficiency with respect to the defect or omission as provided in Section 910.8, except that no notice need be given and no waiver shall result when the claim as presented fails to state either an address to which the person presenting the claim desires notices to be sent or an address of the claimant.
Ca. Gov. Code § 911