Missing _data Folder and more

Audacity Version 2.3.2
Mac OS Mojave 10.14.3


I recorded directly on Audacity a group of files for a project. For some reason, the first 20 files have their corresponding “_data” folders with the .au’s. The remaining 21-31 files I recorded do not have “_data” folders. I have tried Spotlight Searching for them, searching all over the computer, but to no avail. There were also Audacity .aup’s made after this group and they all have their “_data” folders.
Can anyone tell me why we do not have these folders and where might they be?

I came across this problem when I tried to open one of these .aup’s and I’d get the error message “Missing Audio Data Block File(s)”. We either “close the project immediately with no further changes” or “treat missing audio as silence (this session only”. Then, when we play the files there is no sound and a flat line. On other .aup’s we have also received the “Warning - Orphan Block Files.”

I’ve tried looking in the Audacity Directory to find any autosave files, but there is nothing there either. I checked how much storage my computer has because I read that that might be a problem, but we have plenty of storage. The files have simple names and they were never changed from their original names either.

Any help would be greatly appreciated as those files are very important.

Unless they have been moved, deleted, or renamed, they will be in the same folder as the .aup file.