DNI_SMTDDS-MantraSystem1.2 [Ace] Error when learn skill

Hi!! this is my firts time here ad i have an issue whit this script, if one of you have the kind for helping me out this trouble.

well i start saying, its start fine, you get gold, buy the mantra, and the when you try to master it whit the guy that give you "AP"

makes an error in game like this (firts photo)

https://www.dropbox.com/sc/c2toqid5fu8jvri/zDoKE2EGQw

https://www.dropbox.com/sc/g4ukcigo62qxqdi/GfiBTxvyoP

And then when the leader actor master a mantra in battle marks error line 520:NoMethodError occured (second Photo)

both errors only happen when the leader master a mantra, i was hopping to use this script in my fan game but i can

fix this error. the demo is this page:

http://dairuichidoro.blogspot.mx/2013/04/rpg-maker-vx-ace-dni-smtdds-mantra.html

i be very happy if somebody want to help me

THX :D