ID:1324640
 
BYOND Version:499.1199
Operating System:Windows 7 Pro 64-bit
Web Browser:Chrome 28.0.1500.72
Applies to:Dream Daemon
Status: Unverified

Thus far we've been unable to verify or reproduce this bug. Or, it has been observed but it cannot be triggered with a reliable test case. You can help us out by editing your report or adding a comment with more information.
Related code is this on mob.Logout()
var/savefile/f = new()
f << src
world.Export("blahblah", f)
del src


Faulting application name: dreamdaemon.exe, version: 4.0.499.1199, time stamp: 0x51d4b9ba
Faulting module name: byondcore.dll, version: 4.0.499.1199, time stamp: 0x51d4b985
Exception code: 0xc0000005
Fault offset: 0x000962a3
Faulting process id: 0x270
Faulting application start time: 0x01ce812b94b544ff
Faulting application path: C:\Program Files (x86)\BYOND\bin\dreamdaemon.exe
Faulting module path: C:\Program Files (x86)\BYOND\bin\byondcore.dll
Report Id: 2be48b5f-ed1f-11e2-8e4b-20cf30e81171
Your crash info says that's 1199.
Does your mob contain any /icon vars (not mob.icon, but an actual /icon datum), anything related to zipfiles, or anything using databases?
Mob structure for this test was:

atom/movable
animate_movement = SLIDE_STEPS
var/speed = 1
var/tmp/move_time = 0
var/tmp/transferring = 0
mob
icon = 'mob.dmi'

mob/player
icon_state = "player"

var/hp = 100
var/maxhp = 100

var/attack = 4
var/defense = 6

var/server_loc = ""

var/instance = ""

var/server = ""

var
last_x = 0
last_y = 0
last_z = 0

var/tmp
north = 0
south = 0
east = 0
west = 0
mob/player/var/list/party = list()


And in write, I was doing this:

mob/player
Write(savefile/F)
..()
F["server"] << world.url
F["last_x"] << x
F["last_y"] << y
F["last_z"] << z
F["icon"] << null
F["overlays"] << null
F["underlays"] << null
Weird. According to my trace, the crash occurred in DecRefCount() for an internal object of the kind used by the /icon datum (and others, but mostly by /icon). But your structure there shows nothing of the sort. Then again, this same code might have been reused by a different function, so I'm still looking.
I'm posting a followup on research I've been doing on this bug, both yesterday and today. The crash is most definitely happening in DecRefCount() for an internal object. These objects are only used by the /icon datum, zipfiles, and database connections; I believe the culprit is an /icon datum--if not in the mob itself, then in the mob's contents or in something connected to it.

Per my chat with FIREking, the code has since changed and this crash is no longer occurring, so there is no way to determine the cause of the failure. As a result I'm moving this to Unverified until we have a more concrete test bed.
Lummox JR changed status to 'Unverified'