I can't open any of my audacity projects. What can I do to fix this issue?

My audacity program updated to a newer version called “audiotonic - audacity rebuilt for windows 10” and now every time I try to open one of my audacity projects, a message pops up saying “Cant open project file. This file was saved using Audiotonic You are using Audiotonic 2.4.2. You may need to upgrade to a newer version to open this file”. Can someone please help me? I don’t know what to do.

see this post: Opening AUP Files - #15 by steve

Yesterday on 11/29, I had the same issue. When I clicked my Audacity shortcut, it launched a new app called Audiotonic with a tagline that it was the improved updated version for Windows 10. I made the mistake of opening my full book file to finish it, recorded a small section, and saved. I re-downloaded Audacity 2.4 and I get the same message as jademan below when I try to open that file. My other audacity files, that I did not open in the hackers (seems like a hacker anyway) app, can still open in Audacity. It’s only the one I used in Audiotonics. I’m assuming the hacker app had the old Audacity version.
Is there any way to recover that file?
Thank you.

There are full instructions here: Opening AUP Files - #15 by steve