script not found in Challenge

[digger57 10]

Every time I start a challenge flight, I get this message:

"script ca\Data\ParticleEffects\Scripts\init.sqf not found".

After that a challenge mission is loaded and I can fly, although there's still that hiccup in the simulation every 3 seconds (I mentioned that earlier on in this forum and still haven't a clue what's causing it).

I'm running TOH (updated) on Steam ;) and I have checked the file-integrity several times.

greets

Digger57