Run through Tanaris - end up in Caverns of Time.

[ZedMatey 1]

Happened several times today and I've seen many other players experience the same thing.

The title gives away the scenario, but I'll explain in more detail.

On mount travelling south in Tanaris on the east side of the map (close to Caverns of Time) when suddenly I disconnect. Upon logging in I'm the caverns of time (location inside is random, I've never ported to the exact same spot). There is no way out so you have to hearth. On one occasion I instantly died and had no way to access my corpse to resurrect - upon relogging I was able to spirit rez close to gadgetzan. 

This is a pretty major bug which has essentially cost me time and gold - the cost is insignificant as long as this ridiculous shit is fixed ASAP.  

[Roxanne Flowers 15]

This behavior appears to happen ANYWHERE involving subterranean multi-layering of the world.  If there are two possible vertical locations (on the surface and below) the game will apparently try to "double position" your character in both and promptly bug out and disconnect you.  The behavior is very similar to the the Hunter's Eagle Eye spell, which would transfer your point of view to a location other than your character's actual location ... and then when the spell terminated the game client would think you were in two different locations simultaneously, bug out and disconnect you.

The difference here is that when logging back in, the game client "persists" in its False Positive Of Stupid and thinks that you "belong" in the lower/subterranean location rather than up on the surface of the world where you were supposed to be.  This then causes your character to "fall through the world" from the surface into the subterranean location (taking falling damage for your troubles) and bringing all kinds of "Wait, what?" down upon you.

This behavior would appear to be happening on EVERY server, and my guess is that there's a coding typo somewhere that is making it happen (someone missed a semicolon somewhere sort of thing).  Those are ugly to try and track down.

Long story short ... stay away from areas of overland that have subterranean passage spaces "under" them until we receive notice that the Elysium team has found and neutralized this bug.