I had all these questions I wanted to ask on here as I tossed and turned in bed all night, but now I don’t remember them!
Whenever I become lucid it seems like everyone disappears. I mean, one moment I’ll be in a building full of people and when I turn lucid (and usually look up from my hands) they’re gone, and the building is empty. Right now I’m working (patiently) on improving my LD stability, but in the future I plan to interact with people. Why do the vanish and how can I keep them there?
Yeah, about 50 percent of the time,that happens to me. But the more i look around(like in buildings), i find more people. Try looking in buildings. If that doesn’t work, you’ll have to create DC’s by expecting them to be there. For example: When i enter this building, there will be lots of people to talk and interact with.
I’ve had lucid dreams a few times, but there were always people. I dont think i’ve ever tried to interact. Maybe I should soon.
Out of all of mine, only one had people 
so your not the only one
My LDs usually have people, and i frequently interact with them (showing off, convincing them that they’re dreaming, etc) but when they don’t, i usually spawn people by wishing they were there, such as “I wish to see ____” or just randomly walk around and some will appear
I’ve heard of people having this problem, although I’ve never had it myself, maybe because it’s happened to you before you now expect it to happen so it does. So it might just be that you need to change your expectations of what will be there when you become lucid. If you expect there to be people, there probably will be.
I usually walk through doors thinking “Someone’s going to be in here”… sort of as a mental command.
You could try calling someone’s name, too. Or yelling “HELP!” or something.
I haven’t had this problem before. One time, in an LD, I did call someone–my mother, in fact–and let her know that I was dreaming. If you’ve got a cell phone in the dream, you could try calling someone. If you don’t…well, you could have a cell phone if you wanted a cell phone. 
Thats because first you dream then because you are surounded by people it comes into your mind that you dont have frineds so you RC then they disappear lol
Just joking dont take me seryous
I have had this same situation on me too on my second LD. I went to my home but there were no-one there, when there is usually a lot of people.
But I didn’t worry it on my LD though since I didn’t really need or miss them. I focused on more important priorities. ( Like trying to fly 
)