Guild Wars 2

I have the same problem. During map loading I get the same error as wQnxy.7529 mentioned

Game crashed 2 times for me. After 3th time I was managed to finish this mission. All I do was to go after Zojja instead of Logan.

Also as Kingold.8569 mentioned he did not destroyed any walls. I remember that I destroyed just one, so this information might be also helpful.