Here's how I managed to get vox working. First I did this that some of the developers have posted on other threads:
- Close Loop by selecting Quit from Status Icon - Remove Folder ~/Library/Containers/com.coppertino.VOXCloud - Run command in Terminal.app: killall cfprefsd
- Open Loop - Login And Wait for your Library being available on iOS.
Then after logging back in again Vox was uploading without halting any more. Then I also managed to get the artwork working by re-embedding all the artwork into the files (I used 'fetch art' in the swinsian player, which I'm running a trial of, and made sure 'append album art tags to files' was ticked in prefs). Then after checking with finder that all files had art embedded, I deleted and re-uploaded albums with missing artwork then they worked. That was going to take AGES though and seeing as I'd already messed up my library by removing and re-adding the watched folder in loop, I decided to make a new Vox account (as I'm only in trial anyway). After that I selected my library as a watched folder again, it recognised the files that already had artwork before as being on the server already somehow (Vox users with matching files share files?), then uploaded the remaining albums that now had artwork. Since then everything is working fine, Vox on my Mac, iPhone and partners Mac all show every album, with art, and no missing files. Not had a problem since.