BUP offset discrepancy with IFO header

[3gemiha5527136]

When I ripped a Ballet Video named E3XCELSIOR, I noticed two error messages about calculated BUP offset not matching the ones in IFO headers (bold, italic, underlined).
I wonder what this error message means and what is the effect during playback.

Here is a copy of the error messages as well as other information:
MakeMKV v1.9.3 win(x64-release) started
Debug logging enabled, log will be saved as C:\Users\User/MakeMKV_log.txt
Using direct disc access mode
Calculated BUP offset for VTS #1 does not match one in IFO header.
Calculated BUP offset for VTS #2 does not match one in IFO header.
Title #1 was added (17 cell(s), 1:59:09)
Title #2 has length of 20 seconds which is less than minimum title length of 61 seconds and was therefore skipped
Title #3 has length of 15 seconds which is less than minimum title length of 61 seconds and was therefore skipped
Operation successfully completed
Saving 1 titles into directory G:/BALLET VIDEOS/EXCELSIOR
AV synchronization issues were found in file 'G:/BALLET VIDEOS/EXCELSIOR/title00.mkv' (title #1)
AV sync issue in stream 1 at 0:48:06.403 with duration of 76.666ms : audio gap was filled with silence

[Woodstock]

It means there was some funny business done with the directory structure, and that MakeMKV had to work around it. As long as you don't get a message about failing to save the file, the playback should be fine.