A crash when the Character button is clicked

[temnix]

Is this situation familiar to anyone? Maybe it will be helpful to explain when I get this error. I'm using a spell setup that links the caster of my curse with the target. When the caster moves, the target receives a harmful effect (normally more frequently than once a second, but I put in limitations to keep this to 1-second intervals). The arrangement is as follows:

Spell 1: Living actor, cast at Preset target, delivering spell 2. The original saving throw is here.

Spell 2: Living actor, uses a very quick custom projectile, target Original caster, delivers Remove effects for Spell 2 as the first effect (in the hopes of averting the topic crash, only this doesn't help) and as the second effect Apply spell on movement for Spell 3.

Spell 3: Living actor, no projectile, contains the harmful effects for Preset target and Cast spell at Preset target, the spell being Spell 2.

Overall, Spell 3 delivers the curse payload and recasts the spell that establishes the link between the caster and the target. The caster keeps walking, so Spell 2 is immediately triggered again, and so on. It's necessary to have a real projectile, one with speed, in Spell 2, because if the walking condition is reintroduced to the caster immediately, with an Instant/Permanent until Death timing, and the caster is moving, an infinite loop develops, leading to a direct crash, while if Spell 2 is put on the caster with a Delayed/Permanent duration (delayed by 0 seconds), the game crashes as soon as it's paused. Neither crash is the one I'm asking about here. They are both familiar and avoided by casting Spell 2 at the target with a real traveling projectile, only so fast that there is no discernible delay. This is a fine system, but it's marred by a different crash, which happens not every time, but occassionally, when I click on the Character button while walking away my curse-caster. It's kind of hard to catch, but I have had no crashed when clicking on the Inventory button and switching to Character from there. Apparently something happens to the caster just in that nick of time when I access the Character sheet, but all I put on him is this conditional walking-casting. There is no change to statistics, title, name, anything else. Why would there be crashes?