I play the five-string banjo, but not well at all.  Steve Martin plays the banjo very well and he also writes songs for the banjo.  One of those songs, Daddy Played The Banjo, ends with these lines:

Now the banjo takes me back, through the foggy haze,
With memories of what never was, become the good old days.

These lines immediately came to mind when I read the Court of Appeal's opinion in Dupree v. CIT Bank, N.A., Cal. Ct. of Appeal Case No. A163903 (May 31, 2023).  The original plaintiff, in that case, was a trust.  Several years after the case was filed, an intervener argued that because the trust is not an independent legal entity it could not sue.  When the trustee then sought leave to file a curative amendment, the intervener persuaded the trial court that it lacked jurisdiction to permit the amendment because the action was void ab initio.  The Court of Appeal disagreed:

We see no justification for treating the complaint as if it were never filed, effectively erasing it from the docket retroactively—and thus blocking any curative amendment—simply because MAM LLC, appearing in the case as intervener more than three years after it was filed, spotted an issue of subject matter jurisdiction and objected on that ground.

In reaching this conclusion, the Court of Appeal declined to extend an earlier decision, Oliver v. Swiss Club Tell, 222 Cal. App. 2d 528 (1963), that involved an appeal in which the only defendant that was party to the appeal had been merged out of existence two decades before the case was filed.  In that case, the Court declared that all proceedings were void ab initio.  The Court, however, did not address the question of whether an amendment substituting a successor corporation would be permitted because no such request had been made of the trial court.