Something not working? Nine times out of ten, switching browser / computer resolves the issue.
Malicious software that has been accidentally installed can break your browser by redirecting web requests to pages filled with ads.
Be especially careful when downloading software from the internet as unscrupulous people add malware to the installers and then cripple your computer.
If this has happened to you, you'll want to remove the malware as soon as possible. Microsoft has a free malware removal tool that you may want to try.
Buggy plug-ins & extensions break the web on a regular basis, and can compromise your online security and privacy. Never install questionable plug-ins or extensions. Avoid any that are not absolutely necessary.
These can interfere with your web browser, and break it in subtle ways.
These can interfere with web requests in general and web sockets in particular.
If your firewall / proxy is configured in such a way that it blocks normal operation of this site, your only option is to have it reconfigured. Sorry!