window closes and reopens?

hey there! i just bought a hunter from the trade section, and it seems after that whenever i log into my client, it closes and opens once every 10 seconds or so, resulting in a crash everytime, and i mean, it crashes my pc.. id really like to know if there is any info on this or a fix hopefully?

i googled a lot before coming here to bother people but its hard to fnd info on because of keywords like crash and such..im in the process of re downloading the client but i am also scared because for some reason when i delete my wtf folder, it deletes all my characters?? please someone help!

does it crash when you enter that hunter or before to reach character list ?

Characters and character data are stored on the server, not your machine.
You can burn your computer to the ground, run it through a wood chipper, throw it in the ocean and all your characters and account will be intact.