I just wanted to travel from Ald'ruhn with the guild guide, and she simply disappeared. I have no idea how that happened, but that breaks a link in the transportation net, so I need her back now. Is there any way? I don't mind console commands, as this is obviously a bug.

Stand near where she should be, and use RA
If she still doesn't come back, you can try PlaceAtPC "erranil",1,5,1

The first one resets her position, in case she fell through the floor or wandered away.
The second one will place her in front of you.

Thank you. The first one didn't help, but the second one did. I have no idea why and how she disappeared in the first place though.

She teleported away, silly. That's her specialty.

That's strange.

NPCs tend to move slightly from their position overtime. On my first play some of them, guild guides and silt strider operators, moved into walls or fell off their platforms, and that was on the Xbox.

But that doesn't seem like your problem tho.

You might want to keep your eyes open for her. I had the same thing happen with the silt strider driver from Balmora. I later found him at the silt strider port in Vivec. Seems he wanted to visit. I had already used the placeatPC command so I ended up killing one. :shrug:

I've had the exact same problem as OP had.

My guess is that she somehow managed to fall through the floor or walk through a wall, and then just walk away. I used the console to noclip, and then flew around the interior without seeing any trace of her though... but I guess she was far into the fog by then.
But my noclip was good for something... I actually found the Ald-Ruhn guild steward stuck under one of the stairs. I had been looking for her as well.

Anyways, I got these issues fixed somehow... if they don't start walking through walls again. <_<

If she simply walked (or flew or whatever) away, shouldn't the RA console command have helped?

Now she has disappeared again. :facepalm:

Just happened to me. Same place.
Transported there from Balmora and started a dialogue with her when she just dissappeared. poof.
JUST installed the "Julan Ashlander" companion. Might have something to do with it. IDK

ETA: Reloaded the same game and it didn't happen again. Same circumstances as far as I could tell.

I tried RAing and then the placeat pc thing.
RA didn't do anything and placeatpc put her right where I was on the transport platform. She wouldn't RA from there either.
But my game is GTG after going back to the save from just before. No more glitches like that.