NOTE: This glitch has been patched. Also, no one had class xp removed from using this glitch.
Recently, the Alpha Pirate class skin was made to gain Class XP for Pirate class. However, it gives a lot more Class XP than all other classes. I’m not sure why this glitch occurs but it’s extremely useful.
Also, for those that don’t know, Alpha Pirate was released for the AQ3D Kickstarter many years ago and it is not obtainable anymore.
source
Where can get this class?