Here's a fun one. I was just working on a project in DaVinci today a 2k project that I wanted to recolor. It opened just fine and I started working on it. After about an hour when i was trying to adjust something for noise reduction it would start crashing every time. Now when I try to open it, it crashes and won't even open the project. I have tried to open other projects and they all open just fine. It is only that one. I even tried updating my mac to the newest, and also updated davinci 14 studio to 14.1.1 and nothing changed.
Just a shot in the dark: if Resolve will at least launch and show you the Project Database, highlight the bad project and see if it can be exported. If so, export the DRP, label it "Project Name - NEW" or something like that, then import that project and see if it will open. Sometimes this trick works.