"Rocky ..." points out something that I forgot to mention earlier. I would estimate that a quarter to a third of the models on the web have serious flaws with normals, missing points, etc. and another third have naming conventions for sub-objects that Alice won't accept (specifically blank names and names using the xxx.yyy convention). The latter can be fixed by editing the .ase file (you want to convert to this format to import with proper hierarchy) in a text editor - but basic model flaws are almost impossible to fix.