I had been able to run the new 5.4 MSQ dungeon (Matoya's Relict) several times with few issues since Tuesday, save some occasional lag.

On Friday evening, I attempted to run it again and noticed I was getting even more severe lag in the early part of the dungeon, before the game crashed entirely with the "Cannot continue using the application. The data for the following application is corrupted" error message. I restarted the game immediately and was still in the instance when I logged back in (thankfully my group was waiting patiently for me!), but continued to experience lag before the game crashed shortly thereafter with the same error message about the application data being corrupted.

At that point, I deleted the game from my library and re-dowloaded & reinstalled the game.

Yesterday, I tried to enter Matoya's Relict again with a group and immediately had the game crash as I entered the instance, with the same error message I had gotten before. I restarted the game and tried to enter the dungeon solo via Explorer Mode. Had the game crash again with the same error message. I restarted the game AGAIN and tried entering several other instances unsynched or in explorer mode (Hero's Gauntlet, Grand Cosmos, Ghimlyt Dark, Sastasha, Haukke Manor), and had no issue with any of them. I also was able to do numerous overworld activities (crafting, FATEs, visiting some player homes) for several hours with no issues whatsoever. So as far as I can tell, my issues are limited to just Matoya's Relict.

Any advice on what I might do? I noticed that there was a hot fix to the game on Friday and that an issue in Matoya's Relict was fixed. Could it be that my issues might be related to the "fix"?