Mutiple crashes on zone change

sometimes with no message, sometime with exception texture loading message.
sometimes game simply closes on trying to load character.

Updated driver to gpu, cleared cache, reinstalled the game... nothing helps
This existed for a few weeks, but got much worse yesterday...
help.

edit : game not loading with Texture:Invalid header version and some number..

more info: crash can happen anytime, but seems more prevalent on zoning into kingsmarch.
After such a a crash relogin attemps likely end in game crashing before login screen or after trying to load a character..

...