Patch for r171.
Hey, you guys who have a problem with opening projects with Timeline. I had that one before at something like r164 or something. They fixed it pretty quickly but my file back then was lost.
I recommend you keep several copies of your files. It'd be best if you save a big change on cloud and small chances on several files on your machine. As for now, I have 5 saves for Mon-Fri. Just in case things break your save you can get the most recent one with the least pain possible.
As the file that has been broken, one of the team said they might be able to fix it for you, but I found that I could do faster with going back 1 day. You may want to just rework what you've lost if it's a small chances.