This is frustrating - we've been there.
The issue here lies with old website data in your browser (Chrome, Safari, Firefox, Internet Explorer or Microsoft Edge).
All you need to do is clear the cache memory and browser cookies to make this work again. This would mean that the browser will log you out of all websites that you're logged in. Any of your information or saved data will not be deleted. Just follow these steps below -
Go to browser menu (usually three vertically stacked dots on the top right corner) and then settings.
Scroll down to 'Advanced' and go to 'Clear Browsing Data'.
Here, check 'Cached images and files' and 'Cookies and other site data' and click clean. You can leave history unchecked if you don't want to clear it.
Once done, go to the website again and it should work.
Here's a small snipped for Chrome (Firefox below) that will help.