Storyline: Invalid or Corrupt File

New issue today/yesterday with our team. With Storyline 360 files that have been working great for days or weeks, someone is working away in the file and/or tries to open the file and it all goes bad and we get the following error message: "This project is invalid or corrupt and cannot be opened. It may have been created in an earlier version of Storyline.". 

The file was NOT created in an earlier version of Storyline. We have only ever used SL 360. Our own tech people are working on their end to see if the problem is in our system but wondering if any of you fine people have any ideas or have experienced the same issue and know the fix? Right now, I have lost at least one file unless I can find a way to get it back, which sets me back days and days of work, plus whatever it takes to get this back up and running and my downtime until this gets fixed b/c I sure won't be using SL again until I know it is working properly.

All other file types (pdf, doc, ppt, etc) working great. We all keep our .story files on different drives and different network locations so I tend to think the problem is not with our network - how could multiple network locations go bad all at once for just one file type?

I have put in a ticket with the SL folks. I also made sure my Articulate was fully updated, as well as Windows.  I'm  at a loss. :(

I'm attaching the original file and curious to know if anyone else can open it or if the error persists.  

Thanks for the help!