Tom,
Yeah, unless you have a support contract with Microsoft, you're not going to get much help. That's just the way the business works. That's also why forums exist.
Very unfortunate that you do not have a backup. I know this is stating the obvious, but there is a lot to be said for save and save often and do backup on a regular basis. One other tip, I always use Save As back to the same filename, unless I'm creating
a backup, then I save to a different name. I never use just a straight Save. I'm told it doesn't matter with today's apps, but I've never been burned with my method and I don't have file corruption or bloat issues either.
I'm curious. You mentioned that you saved to PDF. Why is that?
Also, it is rather rare that a single stand alone Project file becomes corrupt. Corruption normally results when the user is doing something different. For example, linked structures, whether external predecessor/successor links between files, a master/subproject,
a resource pool/sharer, a file with paste links, or working with different versions of Project, are much more prone to corruption. Do you have any of those?
John