I tried running autohaven earlier today, and the haven icon appeared in the middle of the screen and stayed there for about ten seconds, then dissappeared and nothing else happened. After re-downloading autohaven, reinstalling java and running an antivirus scan, I was unable to solve the problem. However, I found in the task manager that the Java web launcher ran as a background process and I don't think that it did that before. Also, all of the launchers that I tried to open previously where still running in the background processes. I haven't updated anything on my PC recently, so I have no clue what could have caused it. I couldn't find any other reports that were similar.
Edit: tried several custom clients and all worked as usual, except they crashed a few seconds after I started playing, which is a regular problem of mine. I've never had an issue with the default before.