I have done this many times before but never ran into this. I get the following errors when trying to convert a number of discs.
Not sure where to look next, it isn't a directory or name problem.
MakeMKV v1.10.2 darwin(x86-release) started
Optical drive "DVD+R-DL TSSTcorp DVD+-RW TS-U633F D500d" opened in OS access mode.
Optical drive "BD-ROM WD Virtual CD 1110 1030" opened in OS access mode.
It's highly recommended to install DASPI kernel extension to improve performance.
Using direct disc access mode
IFO file for VTS #1 is corrupt, VOB file must be scanned. This may take very long time, please be patient.
IFO file for VTS #2 is corrupt, VOB file must be scanned. This may take very long time, please be patient.
IFO file for VTS #3 is corrupt, VOB file must be scanned. This may take very long time, please be patient.
IFO file for VTS #4 is corrupt, VOB file must be scanned. This may take very long time, please be patient.
Title #1 was added (1 cell(s), 0:25:51)
Title #2 was added (1 cell(s), 0:25:51)
Title #3 was added (1 cell(s), 0:25:48)
Title #4 was added (1 cell(s), 0:25:21)
Title #5 was added (1 cell(s), 0:25:22)
Title #6 was added (1 cell(s), 0:25:52)
Title #8 has length of 12 seconds which is less than minimum title length of 120 seconds and was therefore skipped
Title #9 was added (1 cell(s), 0:25:51)
Title #10 was added (1 cell(s), 0:25:51)
Title #11 has length of 12 seconds which is less than minimum title length of 120 seconds and was therefore skipped
Title #12 has length of 21 seconds which is less than minimum title length of 120 seconds and was therefore skipped
Title #12/1 has length of 11 seconds which is less than minimum title length of 120 seconds and was therefore skipped
Title #12/2 has length of 77 seconds which is less than minimum title length of 120 seconds and was therefore skipped
Title #12/3 has length of 29 seconds which is less than minimum title length of 120 seconds and was therefore skipped
Title 2 in VTS 1 is equal to title 1 and was skipped
Title 2 in VTS 2 is equal to title 1 and was skipped
Operation successfully completed
Saving 6 titles into directory /Volumes/Movie drive/Superman/Season 1/Disk 1
Failed to save title 0 to file /Volumes/Movie drive/Superman/Season 1/Disk 1/ADVENTURES_OF_SUPERMAN_DISC_ONE_t00.mkv
Failed to save title 4 to file /Volumes/Movie drive/Superman/Season 1/Disk 1/ADVENTURES_OF_SUPERMAN_DISC_ONE_t04.mkv
4 titles saved, 2 failed