MC Resets unfortunately are not known for getting rid of abandoned social jigs, those things that look like ovals when they do become visible and get in everyone's way whether visible or not. One way to get rid of them is to run an MC > Object Stats on the lot in question, select everything with "jig" in the object name, and flush (force delete). The MC Cheats module is required for this in addition to the MC base mod.
The other way is the older-fashioned kind of reset. Retreat to Edit Town, evict everyone from the household to the side of the screen, copy the uninhabited lot down to the bin, bulldoze, replace the lot with a copy, and move everyone back in again without having left the screen. The abandoned stuck jigs cannot survive that kind of reset.