beds dont work properly in some of the worlds i create.

when i go to sleep in a bed it should put me in bed and go to the next day.

what ends up happening is that it tells me that there are monsters near by when there are none so i cant sleep. and when i put it onto peaceful mode i can sleep but it does not save the bed as my spawn point.

1) go to bedroom. (on the second floor of my house far from hostile mobs.)
2)click on the bed (both halves, it doesnt matter)
2)stay up all night trying to find the monster hidden under my bed.