Can we get a list of what to tell users to check on the various devices if they are having log in issues.

Here's one I have on my laptop running Windows 8. I can log in to four of my forums without an issues using IE 11. One of the forums will not let me log in through IE 11. I even set it as a trusted site and still can't log in. I have no problems logging in on the same laptop using Chrome.

Why would I be able to log in to four of our forums, but log in won't work on the 5th forum? Every time I try to log in through IE 11 on the 5th forum, it just kicks me back to the log in screen.