Comment 2 for bug 318186

I found a temporaly and dirty fix.

Rename de config folder for transmission and when it start then it generate a new folder "clean"

$ mv ~/.config/transmission ~/.config/transmission_backup
$ transmission

Then start transmission.

Other fix:
The file ~/.config/transmission/settings.json seems be corrupted and its empty!

You can open these file and put the initial values (from the new folder generated for transmission):
My settings.json (you should be some values)
{
    "blocklist-date": 1232747180,
    "blocklist-enabled": 1,
    "blocklist-updates-enabled": 1,
    "debug-message-level": 2,
    "download-dir": "\/home\/shakaran\/Escritorio",
    "download-limit": 100,
    "download-limit-enabled": 0,
    "encryption": 1,
    "inhibit-desktop-hibernation": 0,
    "lazy-bitfield-enabled": 1,
    "main-window-height": 500,
    "main-window-width": 474,
    "main-window-x": 756,
    "main-window-y": 78,
    "max-peers-global": 200,
    "max-peers-per-torrent": 50,
    "minimal-view": 0,
    "open-dialog-dir": "\/home\/shakaran",
    "peer-port": 51413,
    "peer-socket-tos": 8,
    "pex-enabled": 1,
    "port-forwarding-enabled": 1,
    "prompt-before-exit": 1,
    "proxy-authentication": "",
    "proxy-authentication-required": 0,
    "proxy-port": 80,
    "proxy-server": "",
    "proxy-server-enabled": 0,
    "proxy-type": 0,
    "proxy-username": "",
    "rpc-authentication-required": 0,
    "rpc-enabled": 0,
    "rpc-password": "SyUiMtANj6IBeYED",
    "rpc-port": 9091,
    "rpc-username": "transmission",
    "rpc-whitelist": "127.0.0.1",
    "rpc-whitelist-enabled": 0,
    "sched-begin": 1380,
    "sched-download-limit": 200,
    "sched-end": 420,
    "sched-limit-enabled": 0,
    "sched-upload-limit": 100,
    "show-filterbar": 1,
    "show-notification-area-icon": 0,
    "show-options-window": 1,
    "show-statusbar": 1,
    "show-toolbar": 1,
    "sort-mode": "sort-by-name",
    "sort-reversed": 0,
    "start-added-torrents": 1,
    "statusbar-stats": "total-ratio",
    "trash-original-torrent-files": 0,
    "upload-limit": 50,
    "upload-limit-enabled": 0,
    "watch-dir": "\/home\/shakaran\/Escritorio",
    "watch-dir-enabled": 0
}

The major problem is only a settings file that it is empty! Please fix this bug, it seems simple to fix.