Problems with saving to external USB Flash Storage I have an external USB Flash storage which is generally realiable.

When editing text files on the drive I often get the message:

The document “…” could not be saved. The file doesn’t exist.


However, sometimes it does save successfully.

I have formatted the flash drive first as ExFAT and later as FAT32 (it is 64Gb); FAT32 appears to be a little more reliable, but it hasn’t solved the problem. I have also tried attaching the drive first to a powered USB hub, and later directly to the back. Again, it doesn’t help.

What might be causing this problem, and how can I fix it?
From your problem description your filesysyem might be damaged.
Check this with Disk Utility &gt; verify.

If Disk Utility does report any error

then fix them.

Next run verify many times (10 is what I use) on your USB key.

If errors appear,

then your USB is aging and start to behave
badly when heating,
in this case: change it;

else problem fixed.