I've looked at the songfile now and unfortunately it opens here... Though I can't be sure it's opening correctly, there are some errors in the console for instance.
What version of MusE are you running?
If you start muse2 from a terminal and try opening the song, are there any warnings/errors written in the terminal before it crashes?
I get warnings that could be traces of the deleted tracks you were referring to:
Route::read(): track <fluid-0> not found
Warning - route invalid. Ignoring route!
I'm running the development version of MusE from here https://github.com/muse-sequencer/muse/
if you are comfortable installing from source, do try that version.
One last thing. When MusE saves a new version of the song, it leaves the last save <song>.med.backup. You could try opening that and see if it still works.