There was recently a server crash. Right before the crash, I finished some quests in Heiron and decided to turn them all at once. When I did, the server crashed and upon logging in I noticed there was a small rollback as I was standing in a different camp. My quests were completed, yet my XP was rolled back, so technically I lost a tons of xp. I know it doesnt sound like a big deal but leveling around 40-44 is a pain in the ass and I was about to hit 43 already, now I have like 1/3 of my xp bar, without the quests to finish.
EDIT: nevermind, I remember incorrectly and I just hit 42 before the crash, sorry