This is usually caused by a browser issue that is very easily resolved.
You will need to delete the cookies and cache on your browser, here is how to do it.
Safari:
In the Safari app on your Mac, choose History > Clear History, then click the pop-up menu.
Choose how far back you want your browsing history cleared ('all time').
Clear data.
Chrome:
On your computer, open Chrome.
At the top right, click More (3 vertical dots).
Click More tools and then Clear browsing data.
Choose how far back you want your browsing history cleared ('all time').
Check the boxes next to 'Cookies and other site data. and 'Cached images and files'.
Click Clear Data.
Firefox:
Open Firefox and click Menu (3 vertical lines) then Preferences.
Select the Privacy and Security panel.
In the Cookies and Site Data section click Clear Data.
Check the boxes next to 'Cookies and Site Data' and 'Cached Web Content'/
Click Clear.
If you're still experiencing issues then get in touch with us and we'll help you out!