Sim stuck on property

@bev6usa 

• Check if the guest is stuck there behind a door that's locked to them (don't ask how they can get into the door that's locked to them but not out, but it's a thing.
• Or is there anyghint that may possibly be blocking their path that they managed to get themselves stuck behind? If there is, move it.
• Do you have the option to ask them to leave or tell them to go home? Even in the mean interactions? (This may not work if they aren't leaving on their own anyway and are not blocked. 
• Write down their name and hunt them down in Manage households:
  ...If they live on a lot in the game you can enter their household and choose 'bring home' on them. 
  ... you can open the household in CAS and delete the sim.
  ... you can delete their whole household.
  ...you can enter their household and make sure they have a home or move them into a home, assign them a bed, and help them out to take care of their needs if they are just wigged out
• If you have testing cheats on, you can shift-click them and make them happy in case they are out of their mind because of red needs, then tell them to go home or try some of the above.
• If you leave the lot without saving and go to the main menu, or even if you do save, sometimes they will be gone when you come back. 
• If you play another household for a day and come back sometimes they are gone.
• In testing cheats I think there is even an option to kill them, if you're really over dealing with them.

There are other things you can try if none of these things work, but likely one will. There are some options at this link also.

They have tried to leave on there own and they have been asked to leave. They have also been invited into the house but every time they try to leave they can't. There is nothing blocking their path so I don't know why they are stuck. They starved to death once and I quit without saving and they were there when I started playing again.

@bev6usa It's possible their needs got very low and they are out of their minds due to it, as sims can get. Please try the possible fix for that that I listed in my other response, and try other things from the list. Can you share a screenshot of them and their surroundings? Do they show a thought bubble (like the red "x" no route one)? Can you also get a screenshot of whatever the thought bubble shows?