Accessing old uploaded files cause error

[rasos]

We've done an upgrade to latest EP 1.5.6 and reinstalled all plugins. When you try to access a file, which has been uploaded before the update, the file is not accessible anymore.
The user gets a {"error":"Sorry, something bad happened!"}
Logfile: [2015-07-11 15:19:37.102] [ERROR] console - Error: ENOENT, stat '/opt/etherpad-lite/node_modules/ep_fileupload/upload/6a7b1b3bb79165f900ceb749c8d3889f.jpg'
at Error (native)
Has it something to do with the newly introduced relative addressing of files in ep_fileupload?
Here you can see the different behaviour: http://board.net/p/testboard2

[rasos]

Found out, that the target directory is not a setting in settings.json and was a link to a data directory, which was overwritten by the fresh install and which I had to establish again:
root@mymachine:/opt/etherpad-lite/node_modules/ep_fileupload# ln -s /nfsdatadir/etherpad-lite/upload/ upload

Fixed.