I spend many hours this weekend working on stuff. When I open Ardour today, its as if I did nothing since the previous session. All the wav files are in the interchange folder, but they don’t exist in the editor space.
There were a lot of punches too, so a love of wav files that are critical to have in the correct area of the editor window.
Any help? What could have caused this?
I’ve never heard anyone report behaviour like this before. Using snapshots could theoretically cause it. When you start Ardour, and the list of recent sessions is presented, is there an expander arrow next to this session name (indicating that there is more than one snapshot of the session) ?
No expanded arrow, just the name of the tune. I do not use snapshotting, unless it does it by itself.
Here are some additional observations, there are 2 songs I have this issue with, and I was actually able to recover one:
Song 1: The song1.ardour and song1.history files had an old timestamp on them, from weeks ago when I last worked on the song. However, there were song1.ardour.bak and song1.history.bak files with a timestamp of yesterday. So, I renamed the .bak files and viola, my edits appeared. How could this have happened, where the .bak files are a newer timestamp?
Song 2: Same situation as song1, except when I renamed the .bak files, it did not recover my info. Modification dates, wav files, all were correct, just nothing in editor window shows any progress after a few weeks ago when I last worked on it.
So, I have 1 song that has the issue it seems. I could rebuild the wav files, but man I hate the thought of aligning everything perfectly. They are vocal tracks, so they need to be right.
What version of Ardour you are using ? I’ve been using Ardour since version 2 and never had anything like this happen with it.
However I have had files disapper at work on a Mac HFS+ filesystem because of faulty harware. You may have some filesystem corruption or worse the hard drive may be failing. It might be best to backup your data while you can 
When I had files disappearing at work I begun to save my Pro Tools session daily with a new name. I added text “Version 002” to the session name and increased the number with every new save. In this way I minimized the work I lost if the session file disappeared. If you save with a new name twice during a work day you can lose at most a half days work.
In case you only have one session file and that gets lost you lose all work. Session files are small so it’s a very cheap “insurance” against accidents.
I hope you get your session restored somehow
I was using 4.6, but now that you say that, it was 5.4 that I opened the songs on Monday after recording everything over the weekend in 4.6. Not sure if this has anything to do with it?
Everything is backed up to several locations, may be time to get a new hard drive JIC.