in mangos core files open dbcenums.h change 80 to 255
// Client expected level limitation, like as used in DBC item max levels for "until max player level"
// use as default max player level, must be fit max level for used client
// also see MAX_LEVEL and STRONG_MAX_LEVEL define
#define DEFAULT_MAX_LEVEL 80
// client supported max level for player/pets/etc. Avoid overflow or client stability affected.
// also see GT_MAX_LEVEL define
#define MAX_LEVEL 80
// Server side limitation. Base at used code requirements.
// also see MAX_LEVEL and GT_MAX_LEVEL define
#define STRONG_MAX_LEVEL 80
in mangos conf max player leve lset to 255
add 255 player levelstats , classlevelstats and petlevelstats
ofc atm with 3.3.0 core the bug is that you cant see the xp bar but you can level and get xp so its no problem
if anyone want i can post 255 levelstats and 255 xp gaining to...