Your vix file seems to be too large for the wxWidgets XML parser to handle. It's stuck in their someplace trying to read the file. For the Convert tab, we use a different XML parser that can handle these things better, but it's a bit of a pain to use. I'll try and get the vixen import to use it which hopefully fix this.
That said, importing 27K channels this way is going to REALLY suck no matter how you look at it. Rendering time is going to be awful.