**Spoilers below:

I've encountered a few problems with ED-E. First, when I realized how fragile he is, I made him wait for me in Good Springs while I explored. When I encountered the first catch-phrase in Novac, he wasn't with me, but I was still told that I received a quest, and apparently he said something that I completely missed. Is it possible to put whatever he says in the Notes section for future reference? He's said nothing since then, despite exploring through Helios, Boulder and elsewhere. I'm afraid the quest script might be broken, and I'd hate to have to FAQ this quest line.

After that, I made sure he was with me at all times. Now he has vanished altogether, although the engine treats him as still alive-- because I still have his perk, his quest, and NPCs keep saying "Nice robot," to me. He disappeared in the Mines in the NorthWest of the map, the one with Lakelurks in it. He was with me until I went swimming and had to fight several lakelurks after jumping out of the water: the water with the supermutant corpse in it with the Multiplas gun.

When I left the mines, I realized he wasn't with me. I've gone back inside, searched everywhere I can find, and he's not there, and there are no green pips on my compass except for Boone, who is also with me. I'm in a bind, because playing hardcoe mode, I mainly use the autosave. My last savegame is hours before (not a huge deal, but not very fun either.)

Was this caused by a pathing issue? Did ED-E fall through the world? Did he drown, die, and the engine not know how to treat it? Is he still with me but somehow phased into another dimension?

Please look into this for future patching potential, and thanks for an otherwise exemplary and amazingly novel experience.

I had Cass disappear when I told her to wait. She wasn't there when I came back and not in her usual spot in the mojave outpost either but I still had her perk and couldn't recruit anyone else. I was searching around online (don't have the link anymore), and found a suggestion that if your followers disappear to go to vault 22 and use the elevator (you might have to repair it if you haven't completed the mission), and they will appear after. It seems pretty random but it actually worked. Hopefully these things will get patched up

The same exact thing is happening to me. Its frustrating because I need different companions to continue questing. I don't even have the robots dang perk at least.

I told ED-E to go wait for me at the Lucky 38 while i took rex to go get his head fixed. When i got back to the presidential suite ED-E was nowhere to be found. It svcks because he had some valuables on him and i like him better than rex, hopefully this will be addressed in the patch. Does anyone know where he might be otherwise? I Had this same problem with rex but i found him with the King. I dont know where to look for ED-E

I lost him round about Vault 34, but before I went inside (also before I went to Lucky 38for all those who tell me to go there). I have searched all around there to no avail, he is definitely alive as I have his perk and cannot gain another companion while he is "with me".

I also tried waiting the seven days like suggested but that hasn't worked.

They better fix this in the patch by making companions re-appear/reset location, rather than simply making it so they won't disappear in future games, I don't want to have to wait until my next play through to do the side quest that I am on. Not when I am already 47 bloody hours in.