Crash: During Metamorph fight

debug: 727,065,658

Standard League.

+ Was fighting an OP Metamorph in the Precinct Map, Elementalist/Fireball
+ Pop-up error stated Invalid empty filename
+ Clicked OK, restarted client
+ Returned to map, Metamorph still there. Re-commenced battle
+ Pop-up error occurred again, restarted client
+ Chose Gladiator/Reave
+ Returned to map, Metamorph still there. Re-commenced battle
+ Pop-up error occurred again, restarted client
+ Can't return to map, out of Portals.

(Didn't include image, it's just the client with a pop-up error).