Ah, this remark might be confusing. The AssetsFix parameters have indeed no effect on live trading, since the parameters are loaded from the broker when available. But you must still have all traded assets in AssetsFix or whatever asset list you specified in your script, just as described in the manual. If Zorro does not know your asset, it can not trade it. Or at least I suppose so. I have not yet tried trading missing assets.

Aside from the entry in the asset list you should also have price histories of those assets, or else you can not test them.