Hi there 
Please open your dev tools console (F12) and refresh the page, then post a screenshot of any errors you see there.
Couple of things could be going wrong:
- A browser extension error could be preventing the world from starting.
I’d recommend trying in incognito mode to check if it works with extensions disabled. - Antivirus or security software could be preventing the world from loading over websocket.
Try to add a whitelist for forge-vtt.com to your antivirus software if you have any, and try opening in browser incognito mode. - Hardware acceleration is enabled in the browser, but the OS is preventing the browser from using it.
Check out How to fix/turn on your browser's hardware acceleration 's section on enabling hardware acceleration for the browser from Windows directly. Sometimes, battery saver features can cause the OS to prevent the browser from using hardware acceleration. - The world size is too large, and the world fails to load over websocket.
Check out World Size Check for more info.
Hope that helps!