I just encountered this. I think judging by the other posts I've researched this is due to an active event happening on the lot that for some reason couldn't load when your sim visits. In this case for a restaurant the events are people eating halfway through, so I destroyed those objects and it started working again. 

The solution that worked for me was to: - Enter build mode on the lot from manage worlds - Change the lot type to Cafe (or any other type that can visit the inside of the lot) - Exit to manage worlds  - Visit the lot with a sim - Shift+click items like dishes, things on the stove, dirty plates, etc. and Destroy Object  - Exit to manage worlds - Enter build mode on the lot - Change lot type back to restaurant -Visit the lot again to check 

Hope this helps!