I am making an ability that reduces a unit's health to 50% of their maximum. I'm using a create persistent, with the periodic effect of dealing 1 damage. I gave the persistent the periodic validator "life > 1/2", but this appears to do nothing, as I get a stack overflow error.
if your period duration is 0 you need to put your periodic validator to periodic effects (i assume damage effect?) also, otherwise it will be infinite cycle, because persistent won't get chance to perform validation.
so, every time you use period 0 you should put periodic validator to periodic effect as well.
If period 0 sec is not the case then you probably doing something wrong.