I have been using Audacity (3.0.2) on my MacBook Air the past few days and have several files I have been working on. I noticed tonight that a new version was out and decided to download the new one. imagine my dismay to find that the new one doesn’t recognize the files I spent the whole last week working on! Worse yet, now the older version won’t open them either! Did I screw up? All that work for nothing! 
The message I get for either version is as follows: "Audacity did not recognize the type of the file ‘/Users/danieldehner/Documents/8. carol Sing soprano part.cdo’
It also suggests “Try installing FFmpeg” and “For uncompressed files, also try File.Import.Raw Data”
Please disregard this post! Found my mistake!
Perhaps you could share the solution for the benefit of anyone that has the same problem.