DJHao no offense intended but your English really sucks...
I somehow still managed to decode your post. The filename must be 63 characters long. I tried it and it works! But it still is a lousy limitation and Ableton crew should fix it.
Well I'm having some MP3 problems over here too. When I opened up a mix project from version 6.0.10 two files wouldn't load into the mix. It won't preview them either. Here's Lives status bar message when I click on these files: The file "foo.mp3" could not be read. It may be corrupt or not licensed ...