Originally posted by Falco Lombardiyou mean when you solve a problem, but the server doesn't answer and after a while the browser times it out? -it sometimes happens, maybe once in a week or two. I'm guessing it's because their server can't always handle all the traffic. but when it does that, you can simply refresh the last url (which has all the relevant information about the last problem) and everything should continue as normal.
Does the Chess Tactics Server ever just freeze on you? It does this to me all the time and it won't load again.
if the refresh doesn't work out, but instead logs you out, the server has probably crashed. that's very rare.
one more possibility is that you clicked the board after solving the problem, which makes the javascript hang. (there's no java btw).
a fourth problem is that if your browser caches the pictures, it'll lag immensely. in that case you need to set your browser to always load the pictures and it'll work fine.
other than these four cases, I've never encountered any weird stuff with cts during the 70 000+ problems I've done. so if it's not one of these, it's probably your browser, computer or connection.