Unable to see Visual/ Text on Panes

Hello,
I upgraded yesterday to 3.6 and couldn’t edit my site at all ever since.
Other users encountered similar problems with the older versions and I tried their techniques with hopes to resolve mine. However, I’m still unable to view and edit the my web contents in visual/text formats.

Here’s the method that I tried:
Hosting >> File Manager >> edit wp-config.php
Then I added before “/* That’s all, stop editing! Happy blogging. */”:
define(‘SCRIPT_DEBUG’, true);
define(‘CONCATENATE_SCRIPTS’,false);

Anyone know how to resolve this? Thanks!