"former volume not mounted"

Hello, I have the same problem (my version is 3.3) & the folder path is correct, the hard drive (external/USB) is mounted and visible as well,... relocating the files should solve the issue... well, for me, it has "more or less worked", strangely not every time!... :p)
1) if there are several files in the same torrent
- click on the "files" tab (bottom left)
- click on the area of the file list (on one of the files for example)
- press "ctrl + a" (to select all the files)
then right click => "relocalize" and go find the correct folder then click on "select"
- & finally right click on the torrent file "start" => it should verify the file and get back on track!

2) if there is only one file in the same torrent:
I tried the same method, but it doesn't work, because it asks to save/overwrite the old file... in other words, to download the whole file again, not great! :(
good luck,,
Guibs

Great, it's working!!!!