What does the red X mark mean in the cookies list?

Cookies that are flagged with the red X need attention as they are set prior to user consent or have not been placed in a category yet. 

If some cookie is a necessary or preference cookie, move it to the necessary or preference category to clear the flag. If it is an analytic or marketing cookie then there's something wrong with the implementation of the CookieHub widget. To fix that, make sure you implement CookieHub correctly on your web site as described in the CookieHub Implementation guide.