Once today my sith mauader reached level 55 he stoped recieving 12x exp i am a subscriber and i am up do date on the game can someone help me

the 12xp will only last until level 55, at that point it is meant to revert to the normal level of xp gain.

Yup. You still get pretty fast leveling on Makeb. And assuming you have SoR, start that chain (console on ship) and you'll get to 60 np.

I tried to level my characters to 54 right at the edge and about to level up, then complete a mission and receive 500+ k xp points and been put mid way into 55, but MakeB is a good place for levelling and of course once you start the shadow of raven you do a tone of flashpoints,

 

I use xp boosters and kill every enemy visible while doing the solo flashpoints and class missions, this way I found to be pretty quick levelling to 60

Edited September 26, 2015 by ggregoriou

The X12 experience will end 19 October, I think they will do something else with the experience gain. Keep an eye put on upcomming streams.