When the pattern finder has produced such a file, the fault is not reported to the user until the Test phase.

Additionally, there is a combinatorics problem. Train will produce (2 * WFOCycles * Assets * Algos) prediction rules. Some rules may be simple and others may be huge. All it takes is 1 (?) rogue prediction rule to blow up the file and hit the system limit. It is hard to imagine a set of input signals which has predictive power (enough to avoid runaway tree growth in your library) in all directions, cycles, assets, and algos. That's a statistical came you are bound to lose.

To spare your user some agony, if you're interested, you can
- ensmarten your pattern finder so it bails out before producing absurd output (Ideal)
- tentatitvely compile each intermediate file when it is produced. that way user does not waste time training any further parts of this strat.
- nullify any prediction rules which are over complex. just replace them with return 0. (I'll probably do this in an offline script. but, it breaks TESTNOW.)