all masks missing after upgrade to 22

I upgraded to v22 awhile back and found, later, that all of my masks or nearly all, had been "lost". The images that had masks still have layers but the layers have no masks. The corresponding .comask files are still out there on disk in the catalog directory tree but C1 is unable to use them for some reason.

I contacted C1 support and they said this was caused by a couple of bugs and that it is fixed now, -but- my catalog isn't fixed; only the software is fixed. C1 support suggested creating a new catalog and importing the old catalog into the new catalog. I tried that but it didn't make any difference - my missing masks are still missing. I replied to C1 support asking if they had other ideas and was told, basically,  that I'm SOL. "There is nothing else to try", they say (we tried exactly -one- potential fix).

Has anyone else run into this problem and found a way to fix it?