yes I'm sure that is the only dump file created...
I have other news: previously I said that also ubasic scripts gave same error but actually that was wrong, I misunderstood what the person, that made the test with ubasic, told me.
So I tried to "translate" my lua script in ubasic (simplifying it) and it works perfectly, no crash, no errors on all 60 cams...
Now I have another big problem (but I'll write another post for that): if I use any script my 60 cams do not shoot synchronously, there is a random delay on each cam, sometime small, sometime bigger... We were very worried about that then we tried to use the built remote functionality (no scripts and chdk disabled) and cams are in sync... does this mean that by using script I cannot have sync guaranteed?