Downloads won't start

[monkeY!]

I have used Bitcomet for a while now with no problems but yesterday somthing happned my torrents wont start downloading. I can press Start forever but nothing happens (Not even the icon changes). I download a new torrent and it started like normal. many of my torrents was from TBP but not all of them so it probably dont have with piratebay to do. When i download an old torrent to start up my old download i get the message : Can't access folder. Plz need help // monkeY! sry for my bad english