You seem to be trying to open a bundle created in X1 inside 6.0 yes?
If so it's no wonder you're having problems. You're expecting different versions be not only backwards compatible but FORWARDS compatible as well.
And, FWIW, I don't know of many people who use Sonars bundle files - If for some reason your cwp ever becomes corrupted, you can, theoretically rebuild it from the wavs stored on disc which will not be corrupt.
If for some reason your cwb ever becomes corrupt, that's it, game over, you've lost everything in that project permanently