This is I think related to security in a way - anyhow I have tried other sub-forums with no response so could the moderator remove it if s/he feels it is inappropriately posted.

Sometimes when I run the torrent files using the Ubuntu Bittornado Client there are no problems.

At other times I get: Problem connecting to tracker - ('url error', 'unknown url type', 'udp', udp:tracker.urlname').

The specific udp tracker is in tier 3.

I have practised with torrents that have plenty of seeds. Any ideas why this is happening?