That navmesh warning has nothing to do with the problem.

I can fast-travel into my village the first time. All my interiors work without crashing and I even got rid of the grey-face bug. Happy day, I thought. On the second try I tried to fast-travel to my village in the same session, the game crashed. In my book, this is worse than the NavMesh bug.

It's... Bride of Navmesh Bug!

Yep, painful to say the least. But while you're there your NPCs path perfectly well

Would it be possible for someone to summarize what exactly is happening when, and how maybe to avoid it?

As far as I understand from posts here and there:
If a location has a new or altered navmesh, you go there, and after leaving you fast-travel back, the game crashes. Correct? I presume it only refers to the same game session - does reloading reset the issue?
Some people report broken savegames. Is it clear yet when that is happening?
Provided that before 1.5, I installed a mod with a custom navmesh and visited that area. What could I do? Delete the navmeshes in TESVSnip - which records would that be? (Which would, of course, result in the loss of navigation, but better than CTDs...) Open and resave the plugin in the CK? Editing it: what would I need to do?

It would be very helpful if someone could put that information somewhere (here, or in the Mods section) concisely. Thanks.

What face export bug? Gray faces? Because that's not a bug, you're just doing it wrong.

note to self:

NEVER release your mod on the same day a major patch is released (mod does not work for people who have not yet updated)

*hides in shame

That was just one of my(many) theories.

Although it would be funny if that very theory prompt them to look into that.

Yes, it is a bug, but it has a workaround. And no need to be rude about it either.

Correct.

Also correct.

Probably due to mods that used some of the changed records the CK update brought about. I haven't had any trouble with this myself, other than this navmesh issue.

At most, redo your cover edges and refinalize all your navmeshes with CK 1.5. I have noticed that navmeshes done prior to 1.5 will load into the CK and will be missing large portions of the cover data as well as many edge connections to other cells. That suggests at least part of the information that used to be stored in the records was bad and the CK is filtering out the bad parts.

It doesn't do any good though to completely gut your navmesh records and rebuild them. So don't waste the time on that.

Thank you very much.

Regarding that last sentence: "It doesn't do any good" = "it doesn't help"? If correcting and finalizing existing navmeshes fixes the issue, why would completely rebuilding them not fix it? Or do you mean that because it's enough to correct them, rebuilding would be taking things too far?
(Sorry if I misunderstood that, English is not my native language.)

Right, it doesn't help. So there's no point in spending that much time on it. Correcting and finalizing them again is enough, and that takes seconds.

None of this fixes the CTDs though.

If someone uploads/links a plugin that crashes as described, I could http://i.imgur.com/VaIrx.png it, for science, and link it back.