Weird pink room outline in build mode - businesses and hobbies related?

Hey! I was minding my business in build/buy mode when I noticed this weird pink outline around my front patio. Tried making it not a room by deleting a wall, replaced the fences, checked if the wallpaper was cc (it sometimes makes weird effects if not set up right), which it was not. I wondered if it was a for rent glitch, since I have that pack, even though the lot type was a regular residential. I went to switch it to residential rental, and I got a pop-up telling me that (paraphrased) "business areas are not available in some lot types."

I don't own Businesses and Hobbies. I didn't assign a room in residential mode, and I don't know why I'm getting popups and uncontrollable features from a pack I don't even have. 

For reference, this could be a cc thing? The only things I can think of that might cause this is Tmex's Better build/buy and TOOL mod, which I have downloaded as my only build/buy mods. Has anyone else had this problem, and do you have those mods installed if so, or not? I'll try to include some screenshots from my game. I would replicate it without mods but I can't seem to get the lines back to test it.