I'm a new user so forgive me if this seems too basic an issue to raise here. I tried the 30-day trial of MakeMKV version 1.10.10 and successfully backed up one of my 4K UHD Blu-ray discs to a NAS. So I purchased a licence and then noticed a message saying an update to version 1.12 was available. After installing the update I found Make MKV could no longer Open any UHD discs, including the one I'd previously been able to backup. So I uninstalled version 1.12 and reinstalled vesion 1.10.10 and it's working again. So, unless I've missed something, it looks like version 1.12 not longer works with UHD Blu-Rays.
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