This kind of problem often happens to me, I log in, choose a world, it loads normally but suddenly it stops loading and a message appears: "Sever is currently under maintenance, sorry for the inconvenience, please try again later." and you are immediately logged out.
1) Try to turn off and then on your router or if you have a cable remove it from the PC device you are using and reconnect it; maybe this problem will probably be resolved, I always try this and it works but not necessarily from the first time, try this multiple times.
2) Clear your cookies and caches, you will be amazed how many of the most common glitches suffered by net surfers can be fixed by simply clearing the browser's cache & cookies & restarting your browser or visit this site http://www.macromedia.com/support/docum ... er07.html;
if you want more details please click on this link viewtopic.php?f=47&t=3050&p=10076
3) Upgrade your Adobe Flash Player to its newest version because this game is entirely built in flash and this is why no downloads are required...
4) If none of what I told you to worked, please PM a Staff member. They will help you.