Try clearing your site settings. Check out this forum post for instructions.
But, if you're unable to get the website to load at all, this probably won't help. You have to be able to get to the site in order for this process to clear the site settings. In that case, try this:
1. Start Chrome
2. Click "View site information" (left of the web address, how you allow Flash).
3. Click the wheel - "Site settings"
4. In Settings, click the left arrow at the top (just left of the name of the current site)
5. Open "View permissions and data stored across sites"
6, Expand "cox.com"
7. Open "watchtv.cox.com"
8. Click "Clear data"
9. Close Chrome
10. Re-start Chrome and go to https://watchtv.cox.com
11. Enter your Cox userID and password when prompted.
In lieu of clearing all cookies and cache which could negatively affect access to other websites that use cookies, this process only clears data related to watchtv.cox.com. This will allow Chrome users to re-enter their Cox credentials to correct an authentication error.