Medium Error:L-EC Uncorrectable Error

[kahasm]

MakeMKV v1.8.6 [win(x64-release)]
GUI version: v1.8.6 [win(x64-release)]
OS: win7-64 ultimate

RED 2 DVD (not blu-ray)
tried doing a write from title : 22 chapter(s), 6.1GB, 21 chapter(s), 6.1GB and 18 chapter(s), 6.1GB but all three gave same error messages:
Saving 1 titles into directory F:/MKV-NEW/RED 2
Error 'Scsi error - MEDIUM ERROR:L-EC UNCORRECTABLE ERROR' occurred while reading '/VIDEO_TS/VTS_14_1.VOB' at offset '20359168'
Error 'Scsi error - MEDIUM ERROR:L-EC UNCORRECTABLE ERROR' occurred while reading '/VIDEO_TS/VTS_14_1.VOB' at offset '20359168'
Error 'Scsi error - MEDIUM ERROR:L-EC UNCORRECTABLE ERROR' occurred while reading '/VIDEO_TS/VTS_14_1.VOB' at offset '20359168'
Error 'Scsi error - MEDIUM ERROR:L-EC UNCORRECTABLE ERROR' occurred while reading '/VIDEO_TS/VTS_14_1.VOB' at offset '20359168'
Error 'Scsi error - MEDIUM ERROR:L-EC UNCORRECTABLE ERROR' occurred while reading '/VIDEO_TS/VTS_14_1.VOB' at offset '20359168'
Error 'Scsi error - MEDIUM ERROR:L-EC UNCORRECTABLE ERROR' occurred while reading '/VIDEO_TS/VTS_14_1.VOB' at offset '20359168'
Failed to save title 6 to file F:/MKV-NEW/RED 2/title06.mkv

I have tried all three titles on both readers:
1) ASUS DRW-24B1ST
2) PIONEER BD-RW BDR-208D

+++++++++++++
other than that, great program, never ever had any other issues.

[kahasm]

I ran it again with debug this time in the log file. attached is full text file