If you have problems with an out-of-date client, you should try downloading the current client version. If you are using a pc, you can just do so on
http://www.minetest.net/, the site this forum belongs to.
Also, I am guessing that some players use old incompatible forks of minetest, so they just crash as soon as they log in. At least that is how I try explain why so many people instantly leave the moment they join. Probably not important.
Edit:
Ok, as you might have noticed, there aren't really a lot of active players(as in, players who actually play there) on M521, my project. It's been like that for a long while, and I think that it does not make sense to keep this experiment going. (Expecially because I no longer have the time to support it even if it where active)
While it was fun at first, back when all those old players where still playing, it's become a ghost town now (npbody's played there for over a year), so I have decided to shut M521 down (this will also shut down S521, the side-server which I created for those players who just wanted to mess around in a not serious, no-rules sandbox-like server, for those who couldn't play on M521) next week on thursday (February, 22nd)