MakeMKV is currently not well. A software update is being pushed from the mother ship but instead of doing it's thing behind the scenes it's completely flipping broken UHD ripping for now with no ETA for a fix. The errors Doug just posted above are symptoms of this sickness.
Just sit tight while the matter gets resolved.
P.S. AnyDVD seems like a decent alternative to makeMKV for Windows users what about those with OS X?
Living Room: Xfinity XG1v4-A cable box + Apple TV 4K > Sony HT-ST5000 Atmos/DTS:X Soundbar > Sony XBR-65X900F Television
Office: Oppo UDP-203 + Apple TV 4K > Sony HT-Z9F Atmos/DTS:X Soundbar (with rears) > Sony XBR-55A1E Television