If your crashes are characterized by the game simply ceasing to exist at seemingly random times without a single error window, prompt, or dialogue whatsoever, and you have a NVIDIA video card, you most likely have what are often simply called the “NVIDIA crashes”.
NVIDIA crashes for Secret World Legends can occur on any NVIDIA video driver 430.39+. The last NVIDIA driver completely free of the crash issue where SWL is concerned is 425.31, which is also coincidentally the last NVIDIA driver to support 3D Vision, amongst other things.
Rolling back to 425.31 guarantees stability. 436.15 is also highly stable for a good majority of players, as well. Later driver version stability varies greatly between players, but some have success on the 441/442 line, and others are alright on 452.06. As of this post, I don’t yet have any substantial data on SWL-NVIDIA driver stability on versions later than 452.06.
If you are unable or unwilling to roll back, some players also find relief by swapping their client from DX11 to DX9. While you will lose some of the DX11-exclusive graphical options such as the admittedly very pretty SSAO, going to DX9 may help as a potential option if rolling back isn’t on the table for you.
I’m very sorry to hear you’re suffering these crashes! The root cause of the nefarious NVIDIA crashes is still being investigated.