So basically somehow one of the Gravestones on my lot (House of Fallen Trees) has become stuck in use, meaning that it cannot be moved. The result of this is that ghost seem to not appear at night anymore. Not sure how it happened but it may have occurred from one of my Sims visiting a downtown lot while a ghost was haunting its grave (Making it Float). Not sure if its related to the glitch but a few minutes before a Sim had put a teddy bear near one of the flowerbeds which disappeared when it was placed on the ground. Now I have had beds get stuck before but unlike beds I can't really delete a gravestone without risking corruption and since ghost play a big role in my story line I would rather keep the graves. I considered moving my Sims out so that the grave would reset itself to normal, but I don't want to have to redecorate the place. I have heard that saving with ghost active on the lot and reloading cause even bigger problems, so this is why I'm posting this.

You could try and use Mootilda's Hood Checker Program and see if it will fix your problem. http://www.modthesims.info/download.php?t=456523

Having a Sim move the grave to another lot and then moving it back seemed to fix this issue. I'll look into hoodchecker on the safe side. Thank You.

This always happens to me. It's something to do with the ghosts making the tomb stones float, yes. I just use the 'boolprop testingcheatsenabled true' and then shift click to 'force error' and click 'reset' and everything seems fine. I haven't checked up on if the ghost still appears after that, though. Might want to look into that before you try it if you're attached to your ghosts.

You can try using insim to select the ghost then delete the ghost only ...so the tombstone is not "in use" anymore