Hmmm...Ive had a similar problem with a project I was working on,I fixed it by replacing all of the animations with the characters bones(GULP),Ill tell you how:
1.preview the model and open up lucario's animation.
2.export all three wait animations,and open pokemon trainers animation.
THIS NEXT STEP IS BIG,AND TAKES DAYS TO WEEKS!!!
3.right click on the wait animations and replace with the 3 you exported.
4.in transform all,click on copy for wait 1,and paste in the first slide of all the animations.
5.You may have to do some bone editing,so do your best.
6.Make a copy of poketrainers motion pac,and click save in brawlbox after your done.
7.put it in fighter in pokemon trainers folder...
AND YOUR DONE!Not to hard was it?
I tried that. It freezes when you select a stage.