Game crashes in Castrum Centri and Castrum Meridianum

I've been having this problem for about 7 months and ongoing now. To clarify, I never used to have this problem and played through the main scenario just fine, and am up-to-date on current patch story.

Up until 7 months ago however, I've had my game crash whenever I go into Castrum Meridianum on Main Scenario roulette, and recently I've been trying to complete my MCH lvl 52 job quest, however it's based within Castrum Centri, and whenever I spend, on average, 30 seconds or so within the area, my game crashes. I don't have this problem anywhere else, and it always crashes within this average amount of time, so at the least I have enough time to teleport out before my game crashes again.

Is this a known issue?