[nmglug] .avi on DVD play VLC

Hi Intermittent problem received Dvd today has been finicky VLC error message say check log where is that log be located? Have played the DVD in part three tries out of perhaps ten tries no go at times seem to override error message? Have been using open disc ,open files and open DVD alternately the later where the error message manafests, I then somehow have stumbled upon the three file .avi choices. choose one click on to play, Where I found the files is a bit hazy? Any thoughts on an unraveling strategy? Thanks, Anthony