The error message: “Audacity failed to read from a file in C:” indicates corruption in the project (AUP3) file.
There are many reasons why this can occur. The most common reasons appear to be:
- Working on projects that are stored on an external drive.
- Working on projects that are stored on “web drives”.
- Shutting down the computer while a project is open in Audacity.
- The computer failing to restore state correctly after “sleep” or “hibernation”.
- Running out of disk space while a project is open.
Ensuring that projects are always on a normal, internal drive (hdd or ssd) before opening the project goes a long way towards avoiding this problem. I would also recommend disabling sleep / hibernation while working on projects, and ensuring that laptops are connected to mains power.
If this problem does occur, in many cases it is possible to recover the project with a special tool that is available here: https://github.com/audacity/audacity-project-tools
Detailed instructions for how to use the tool on Windows have been provided by jademan here: https://forum.audacityteam.org/t/corrupt-or-otherwise-broken-audacity-project-recovery/64162/1