Download all data for S Ori from the aavso website choosing "Space Delimited (not column-delimited)" format. Opening the file in vstar gives "...error in observation source."
Personally, I find the thought of space delimited data to be abhorrent. But if this is a supported format to download from the aavso website, then vstar should open it. I had no problem opening csv or tsv formated data files for the same star.