low exp from mobs lvl 49+

[wilk99]

I get very low exp from mobs lvl 49+, my current lvl is 48. for example mob lvl 49 gives 2k exp. Mob lvl 48 gives 40k exp. What is going on?
Do i need to be in some guild or make some quest to fix it? 
Pls help me and thank you.