[[Warning]: Unable to restore stack! Double continuation!]

Brian thank for ur help, 
when i remove sleep2

then this mesage appear
 

[Warning]: npc_event: player's event queue is full, can't add event 'BotKiller::OnNPCKillEvent' !

 

but its work using sleep2 and temp char variable,
no warning appear

[[Warning]: Unable to restore stack! Double continuation!]

[Warning]: Unable to restore stack! Double continuation!
[Debug]: Previous script (lost):
[Debug]: Source (NPC): botcheck(invisible/not on a map)
[Debug]: Current script:
[Debug]: Source (NPC): botcheck(invisible/not on a map)

i had same issue with my script

 

OnNPCKillEvent:
	sleep2 100;
	if (rand(100) != 1) {
		end;
	}
	mes "[botcheck]";
	mes "answer this";
	next; 

 

 

when someone uses an AOE skill and a lot of monsters killed this message always appears,

 

how to prevent it?

what use the var? or is there another way?

thanks