Well, for starters, I would try changing it to channel 1. import/export operations for modding games are usually pretty finicky, always best to keep it as simple and standard as possible, and once that works you start trying other more complicated settings.
Secondly, that texture, while technically functional, isn't very optimized. Did you know that you can pile up sections of your model that use the same texture? You'd only need one rectangle of "post" texture and every face of the pole can be on top of the other, on top of it. You could get away with making this texture 512x512 with literally zero loss in quality. Just an idea to optimize once you get it working in-game. Looks great other than that.