Lua Error on getting experience

[alexandre freda]

When a player kills a monster, the console shows the following errror:

Lua Script Error: [Event Interface]
data/events/scripts/player.lualayer@onGainExperience
data/events/scripts/player.lua:168: attempt to perform arithmetic on a nil value

stack traceback:
[C]: in function '__sub'
data/events/scripts/player.lua:168: in function 'useStamina'
data/events/scripts/player.lua:204: in function <data/events/scripts/pla
yer.lua:187>​

And the player gets the experience as normal rate, even if the rate is 100x on config.lua or stages.xml

 

[jesus135]

i have this error and idk how to solve you already solve it?

 

[Infernum]

we need your script if you want help
you can't just say something doesn't work and expect someone to know what you're talking about with zero context