When people join my server after changing my name, their data gets wipped and another uuid is created for them instead of the one created before changing their name. I have seen other people have the problem on their servers and it's not to do with my plugins/server.

Someone has made a fix but I suggest if mojang want their community to stay in minecraft then they should fix this issue, some players don't want a extra plugin due to the fact their server could be lagging now because of too many plugins.

The fix: http://www.spigotmc.org/threads/tutorial-how-to-disallow-player-name-changing-not-break-non-uuid-plugins.44142/