Error on persistent

Hey guys, i always used a persistent from here(windbotforum) but few days ago sometime went wrong and i m having some error/issue
error in Persistent script mageshooter:
[" if not name:find('category'..."]:mageshooter:494 attempt to index local 'name' (a nil value)
stack traceback:
[" monsters = convertCategory(arg.monsters)"]:mageshooter:510 in function [" function convertSpellConfig(arg)"]:mageshooter:502
[" local config = convertSpellConfig(spell)"]:mageshooter:793 in function [" function parseConfig(ShooterConfig)"]:mageshooter:779
[" pconfig, _RuneMonsters = parseConfig(Config)"]:mageshooter:896 in init block

can anyone tell me what is that?
if im in wrong section please forgive me..
Thanks to everyone

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Problem solved! Already had help in private msg!
TY - CLOSE