Can't open file made with Audacity and saved to external hard drive

A little background, had hard drive failure. All personal files including Audio has always been stored on external USB Hard drive. Audio files were always saved as MP3 files to be used with MP3 player and this had work fine for a couple years.

After replacing hard drive and loading Window 10 Home version 20H2 build 19042.631 and Audacity 3.0.2. I tried opening a audio file that was previously made and edited with Audacity and I’m getting an error message saying something about this external drive is a FAT drive and Audacity can’t open the file. But if I just click on one of the MP3 files on this external drive Groove music seems to have no problem playing the audio file.

I know before the computer problem I was using Audacity and never had a problem opening the files from this external drive and doing some editing like adjusting sound levels or adding or deleting dead sound.

Probably is something as simple as now Audacity can’t read from FAT formatted drives. Try to copy the file to a NTFS formatted drive and open it form there, that might result.

Ok, but why would this drive that I have used for a couple years and been able to save to and read from in Audacity now be formatted wrong for Audacity to use when a few days back it worked? While installing Windows 10 Home I did have the External drive un-plugged in an attempt to avoid anything being damaged or changed on it.

And the next question I guess would be how to tell what the formatting “FAT or NTFS” is of a drive?
Also is it possible to change the formatting of a drive to NTFS so Audacity can access it? Maybe make back ups of all files on it, reformat and then restore files to it?

Because with the new Unified file project structure we introduced with 3.0.0 although a FAT drive would work - in testing we found that it was all too easy to exceed the 4GB individual file size limit even with small projects - so to keep projects safer we blocked the use FAT and FAT32 formatted drives for open live projects.

In Widows Explorer right click in the drive name and select Properties

Yes, you also do that from the window that popped up when you were looking at Properties. exFAT would also be a suitable alternative.

I know these work as I did all this when QA testing the alphas and Release Candidates for 3.0.0

See this page in the Audacity Manual: Managing Audacity Projects - Audacity Manual

And this page: Updating from Audacity 2.x to Audacity 3.x - Audacity Manual