British Columbia, Canada
The following excerpt is from Kaur v Virk, 2022 BCSC 173 (CanLII):
The proper and valid service of documents involving litigation is fundamental to any further proceedings by which the litigation is advanced and imperative in order for a court to assume jurisdiction over the subject of the litigation. Such a fundamental concept was enunciated over half a century ago. It remains as valued today as it was when Lord Green, M.R. observed in Craig v. Klassen,  1 K.B. 256 at p. 262: It is beyond question that failure to serve process where service of process in required goes to the root of our conceptions of the proper procedure in litigation.