Guild Wars 2

Same thing every time i log in get into character selection. Select character loads a little you can hear background effect. but still loading screen and crashes.
Crash <—*
Assertion: tierDenominator > 0
File: ..\..\..\Game\Ui\Widgets\ObjectiveList\OblAchievements.cpp(1758)
App: Gw2.exe
Pid: 7368
Cmdline:
BaseAddr: 000F0000
ProgramId: 101
Build: 38569
When: 2014-09-09T21:51:50Z 2014-09-09T15:51:50-06:00
Uptime: 0 days 0:00:38
Flags: 0

*It seems like Guildwars 2 is really conflicting with my system or something because after the latest patch I have been crashing in game every time now after 10 mins of play. I have recently updated my Graphics card Asus GTX 570 and Intel bios stuff.
This doesnt happen in other games except for guildwars 2

Also can you guys teach me how to find the crash log? after my game freezes?

Thank you

Processor: Intel(R) i7-2600K CPU
Asus P8Z68-V Pro Motherboard
Memory: 8192MB RAM
NVIDIA GeForce GTX 570*