After some tweaking I finally got a map to load (JUST NOW). It took a while, because none of what I did was in the instructions, that I could see! But, it makes sense after I found the possible issue. I had the exact same errors you were having when I was loading to my server, that a few of us close friends play on. Anyways, I'll try to explain how, but holler at me if you can't get it to work and I'll help the best I can.
You've done everything up to this point correctly, per your post. Although, there are two '.txt' files in the unzipped "\\Compo_Pack 43\Nitrogen-files" folder called "configUI.txt & prefablist.txt". Go ahead and Copy (Ctrl-C) these two files -- or whenever, then open up the directory where you installed the NitroGen World Generator. Inside the Nitrogen root directory open "resources" folder and locate the two files with the same names as the ones in the Compo-Pack 43 folder, i.e. 'configUI.txt & prefablist.txt'. Next rename both those files to something else like "configUI--Original.txt" , do the same for both files! (or rename to whatever you want, it just helps to know what they are later if needed. It's just to prevent overriding them when you paste the files from Compo-Pack 43. Next, paste the two files from the compo pack folder into the Nitrogen\resources\ folder. You can close and now open the Nitrogen Generator
Last step... I believe, (since I haven't fully tested it as I just now spawned into the working map) is when choosing your settings inside the Nitrogen generator app make sure to leave "prefab list" set to Vanilla (default). This is because those files you pasted, are the ones for the "Vanilla Setting", do not select compo_pack 42, … unless you just want to check it if the other doesn't work... just as I may have to do. Sorry I couldn't fully test it before, but it's bed time! If this doesn't work, holler at me and we'll get together and figure it out through Discord.