www.makemkv.com

I'm re-ripping some of my HDDVD to fix issues with 256 SPF DD+ Audio. The first time I ripped them was a long time ago with V1.6.X and V1.7.X.

Some of the discs I previously ripped with these old version do load but the main feature is missing from the titles list. I've only tried 6 so far and had this problem with:
King Kong
The Hurricane

Has HDDVD processing taken a step back since these old versions or is it likely disc failure?

I keep several older versions of MakeMKV specifically for random issues with DVDs & generally the newest for Blueray. It is weird & per dvd it seems, but it is very rare I've had to roll back.

I wonder if these particular discs are just some sort of corruption as it complains of corrupt IFO even though no read errors.

After trying to re-rip over 100 I have a short list of discs which immediately refuse to open but play OK in an HDDVD player:
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