I've been working my way through our DVD library making backup ISOs. A very small number of them fail. In one case, the disc was obviously damaged, but here's the debug log for a disc that won't backup even though it seems perfectly fine.
Debug log started at Sun Feb 4 17:42:08 2024 , written by MakeMKV v1.17.6 darwin(x64-release)
001005:0000 MakeMKV v1.17.6 darwin(x64-release) started
001004:0000 Debug logging enabled, log will be saved as file:///Users/ndw/MakeMKV_log.txt
Using 262272KB for read cache.
Network access is ENABLED, CURL version 8.4.0/(SecureTransport) LibreSSL/3.3.6/1.58.0 (x86_64-apple-darwin23.0) , proxy server not set.
002010:0000 Optical drive "BD-RE HL-DT-ST BD-RE WH16NS60 1.02 KLMN5M80923d" opened in OS access mode.
SDF v098: HL-DT-ST_BD-RE__WH16NS60_1.02_211810291936_KLMN5M80923
SDF v098: HL-DT-ST_BD-RE__WH16NS60_1.02_211810291936_KLMN5M80923
SDF v098: HL-DT-ST_BD-RE__WH16NS60_1.02_211810291936_KLMN5M80923
001011:0000 Using LibreDrive mode (v06.3 id=7FA2657C7667)
005072:0000 Backing up disc into folder "file:///Users/ndw/Movies/backup/LOTR_TWO_TOWERS_SEE_D4.iso"
DEBUG: Code 11 at a=_F{Xft?{WS%,QWI:121263199
Launching /Applications/MakeMKV.app/Contents/MacOS/mmgplsrv
001003:0020 DEBUG: Code 118095996 at %0~')#t2JGP}d+=&8109SA :29394183
001003:0020 DEBUG: Code 0 at %0~')#t2JGP}d+=&8109SA :121263590
001003:0020 DEBUG: Code 1783 at ~:tP{.LI5iY'I2Pd*I7,:213133250
001003:0020 DEBUG: Code 67174400 at ~:tP{.LI5iY'I2Pd*I7,:121265062
001003:0020 DEBUG: Code 1 at ~:tP{.LI5iY'I2Pd*I7,:29394689
001003:0020 DEBUG: Code 2147483647 at %0~')#t2JGP}d+=&8109SA :213130145
I'm curious if this is likely to be an issue with this particular media, or if this is some encoding issue that would effect all copies of this disc. I will probably get a second hand copy and try it out, but I don't have one immediately available.