Since you’ve opened a support ticket by posting here, it would be a good idea to be a little bit more specific about what exact things you’ve tried, so they don’t have to start from zero when trying to help you.
Here are some specific steps to work through; if you can list each step you’ve tried, and what happened when you tried it, you’ll be able to get to a resolution much more quickly. 
There’s also a pretty good forum post that consolidates a lot of the things that can contribute to this issue here – again, list the ones you’ve tried and what the outcome was, so Support can skip having to ask you about each one.