Just a possibility:

I had such script crashes, too. In my case, it had to do with ressource management. My levels needed to much memory. I reduced the entity count and compressed all textures to DDS. Now the error is gone.
From my experience, the Acknex engine crashes by "E1513 - Script crash in SYS" or "D3D - out of memory" on loading too big levels.
Just optimize them, use DDS, reduce the entity count.

Edit: No, this is not nonsense. I`ve got an example here that clearly shows the problem. The E1513s only appear when my levels come to a certain memory size - and only after certain level changes on loading levels. The errors have gone completely since I optimized the levels. And it`s 100% the same script. I didn`t change anything.