command /야간투시 [<text>]:

    trigger:

        if arg 1 is "켜기":

            set {%player%.야간투시} to true

        else:

            set {%player%.야간투시} to false

every 1 second:

    loop all players:

        if {%loop-player%.야간투시} is "true":

            apply potion of nightvision of tier 2 to player for 999 days

마지막 줄에서 오류가 납니다. 어떻게 고쳐야 할까요.

there's no player in a periodical event

apply potion of nightvision of tier 2 to player for 999 days