I have had the r6025 run error since launch, and seems to only occur when the game is very laggy. I have had the same symptons as many of you; npcs and mobs not loading for minutes, invisible walls, droppping through floor, etc. I have found a solution that has worked for me. I simply exit the game, relaunch, and log back in until I log into a non-laggy game. I have three checks I confirm to determine whether the game will be laggy for that particular login.

1: As soon as I log in, the recommended quest/duty list thing should pop up almost instantaneously.

2: When I switch jobs, it should take only 1 second for my character to show that I've switched into the switched jobs gear.

3: Ride a mount and it should only take 1 second for you and your mount to be displayed.

It may take a several restarts of the game to log into a non-laggy game. It takes me anywhere from a couple tries to 10 tries. This has worked for me 100% of the time. I would like to see if this works for others as well. Although I don't consider this an actual solution to the problem, it is good enough for me to play the game without it crashing. I hope SE fixes it soon.