"My Ableton Live set won't open!"

If you've found this post because you're panicking that you may have lost your work in Ableton Live, there may still be hope of recovering it.

A few times I've been unable to open an Ableton Live set that I'd saved previously. My HD would churn away for a long time, and Live would eventually crash and disappear. Very frustrating.

If it was ever to turn out that the .als file was really unopenable, It wouldn't be a complete disaster since I always 'Save as' using an incrementing version number: "MyTrack1.als", "MyTrack2.als". So that if the last file I saved really was corrupt, and unopenable, I'd still have a previous version I could go back to and work from. I strongly recommend saving a new version of your track each time you save.

So far though, I've always been able to recover the current version.

Delete Live's preferences file

On my machine the file is located at ~/Library/Preferences/Ableton/Live 7.0.1/Preferences.cfg. This often solves the problem and its the fastest fix, so try it first.

Remove your plugins

Many times it's been the case that removing a particular .au or .vst plugin from my plugins directory allowed me to open the file again. In particular I've noticed that if I've been using a demo of a plugin, and the demo has expired, then the demo plugin would cause Live to crash on opening a set (I experienced this recently with demos from Nugen Audio). If Live opens a set which uses a plugin that's no longer in your plugins folder, you will be notified by a dialog window, just click 'Ok' to instruct Live to continue loading. If the set loads, missing plugins will be represented by 'empty' plugin graphics. You can delete these or replace them with working plugins.

Remove corrupt audio files

Another thing that can stop a set from opening is if some of the audio files it depends on are corrupt. If removing plugins hasn't helped, try looking in your live set's Samples directory. See if any of the audio files are ZERO kB. If they are, remove them and try opening the set again.

Import the set track-by-track

A trouble-shooting technique that can be useful in this situation is to open an empty set, and import the tracks from the set you're having trouble with one by one. To do this, browse you your set in Live's browser, expand the set's folder using the arrow icon, and drag the individual tracks that have appeared, into the arrange window. It can be a pain to recreate a set this way, especially if you used return effects and master track automation, which can't be recovered like this (afaik), but this approach can still be useful for identifying where the problem is.

Post in the comments if you know of any other tips for those times a Live set won't open.