Tempest Peak freeze + game display oddity

[Torokasi]

Log in pastebin to avoid wall of text.

http://pastebin.com/2CPVMWp0

At the time, was entering the "main" section of Tempest Peak; had just gone down the stairs when the game froze (before I saw progress bars) and began switching between a black screen and Tempest Peak at 1.5 second intervals, approximately.

Uncertain as to cause, don't think I did anything out of the ordinary.

EDIT: Occurred again in Unremarkable Cave, error seems to come up as soon as I attempt to switch weapon sets.

I'm a Mindslayer, so secondary set is a Garnet and the Triple-Edged Sword "The Truth" artifact. I have no mods or addons implemented. Apparently I switched in the pasted error as well right before the crash. Any advice? Makes this dude somewhat hard to play if I can't access that set.

EDIT 2: Sounds like this might be a fixed error already, but I'll leave this up.