WP Update 3.9

Hi, since yesterdays update I’m not able to write posts in the visual editor.
After searching for the problem someone posted a link in the forum:

http://codex.ww.wp.xz.cn/Using_Your_Browser_to_Diagnose_JavaScript_Errors

I checked for the error in google chrome and got this error:
Uncaught TypeError: Cannot call method ‘indexOf’ of undefined
tinymce.min.js?ver=4021-20140412:10

anyone know how to fix this? i disabled all my plugins, but it still doesn’t work!

thanks,
soraya