ive had that problem to. (i think ive had every problem) its a connection error between ur computer and the server host. it shouldnt be hapening on every server. a few things to try are: restart ur computer, reinstall wom, check if java is up to date and working, check to see if minecraft.net is up, and see if u can connect to other servers on minecraft.net. if still u get this problem it might be a bug in the client so give it some time. that error could also be a faulty url so try using wom direct. if all else fails, use the web. search ur error on google or youtube and see if there are any explnations or solutions.