OK, This time I think I have it fixed.

Unfortunately, it wasn't One World that was broken. It's the links to the steam cloud that aren't working. None of the models for the mountains themselves are showing up.

I fixed it. It no longer needs One World.

Unfortunate, this mod is now broken. None of the mountain models will load.

Hulk Hogan approves

I have looked at your screenshot and asked my players if they were having this effect but I could not imitiate it. Thie asset bundle is narrow waterfall, I found it on another workshop here https://psteamcommunity.yuanyoumao.com/sharedfiles/filedetails/?id=1469725554
If that still does not work there is another type of waterfall here https://psteamcommunity.yuanyoumao.com/sharedfiles/filedetails/?id=1169825885 although this one might not be as appropriate.
I did not use real world data for this. It was all done in blender with textures. I had a lot of help from youtube videos to create it and then baked the texures onto a single UV.
If you do plan to use it and none of the assets work, I could make you a quick little waterfall model. It would not be as neat as the asset bundle, but it would cover that area.

Very nice aestetically, looks like it was taken from some real world data?
Also, nice idea for creating small scale forests.
But I have a problem with the asset bundle effects, they are just big black squares for me.
https://i.postimg.cc/8TQvppHW/grafik.png