Hi, the mod is a level editor enhancement mod meant for helping you to make levels, rather then content expansion. I haven't heard of anyone on discord struggling with installation, so that's a bit strange.
If you want to play custom levels by other people, you don't need the mod for that. Level Editor+ doesn't add any new content, haha :)
Check out here for an online collection of custom levels. To play,
1 - Copy a level code from the link above
2 - Head into the level editor
3 - Click 'Load from Clipboard'
4 - Click 'Playtest Level'