This issue may present as a white page with a page icon in the centre, or as a page icon with a sad :( face.
The "d37qvdioltnfzp.cloudfront.net refused to connect" issue is typically a temporary issue and may be caused by a brief conflict in your browser cache.
There is no direct cause for this issue to occur, and it can be resolved easily by logging out and logging back into your account, closing and reopening your browser, or in some rarer cases, rebooting your PC.
To log out, you will see the button on the top right of your learner dashboard:
On mobile, you might need to expand the menu to see this:
Please enter your email and password again on the login screen.