[galaxy-user] Trouble in extracting species on maf imported from UCSC

Hi, When I import a multiz46way maf alignement from UCSC, if is is a whole chromosome, then when I try to "Filter MAF blocks by Species" the list of species does not appear. If I import a small region, it works... Is it a question of size? Although it seems OK when I look at it, could it be a problem in the maf format that I could solve? Thank you, Aurelie