Crashing in loading screen[Mac]
Unfortunately there’s not much that can be done.
If I am not mistaken, this error is caused by the client running out of memory. Unfortunately, due to the way in which the Cider translation layer works the simple fact is that the game client on OS X uses more memory than it normally would, and suffers from memory fragmentation more than it would on a Windows system.
On Windows this issue can be alleviated by using the 64-bit client but unfortunately due to incompatibilities with OS X’s ABI (and how OS X and Windows think the GS register should be used) it’s unlikely this will ever be fixed unless ArenaNet one day decide to write a native Mac client.
You can certainly try playing the game with PlayOnMac and see if you have any luck with this – many users have had success this way. I would also suggest you try lowering the settings you’re playing the game at – especially texture settings and those relating to character limits.
If not, try playing the game on Windows.