This website uses the Shockwave Flash plugin for this game. Do you have the Flash plugin enabled for this website? You can check the Lego block icon at the left end of the location/address bar. See also: *https://support.mozilla.org/en-US/kb/keep-flash-up-to-date-and-troubleshoot-problems *http://kb.mozillazine.org/Flash#Troubleshooting ---- If you use extensions ("3-bar" menu button or Tools -> Add-ons -> Extensions) that can block (wanted) content (e.g. Adblock Plus, NoScript, Ghostery, uBlock Origin) always make sure such extensions do not block (wanted) content. *make sure your extensions and filters are updated to the latest version You can try these steps in case of issues with web pages: You can reload web page(s) and bypass the cache to refresh possibly outdated or corrupted files. *hold down the Shift key and left-click the Reload button *press "Ctrl + F5" or press "Ctrl + Shift + R" (Windows,Linux) *press "Command + Shift + R" (Mac) Clear the cache and remove the cookies from websites that cause problems via the "3-bar" Firefox menu button (Options/Preferences). "Clear the cache": *Options/Preferences -> Advanced -> Network -> Cached Web Content: "Clear Now" "Remove the cookies" from websites that cause problems. *Options/Preferences -> Privacy -> "Use custom settings for history" -> Cookies: "Show Cookies" Start Firefox in <u>Safe Mode</u> to check if one of the extensions ("3-bar" menu button or Tools -> Add-ons -> Extensions) or if hardware acceleration is causing the problem. *switch to the DEFAULT theme: "3-bar" menu button or Tools -> Add-ons -> Appearance *do NOT click the "Refresh Firefox" button on the Safe Mode start window *https://support.mozilla.org/en-US/kb/troubleshoot-firefox-issues-using-safe-mode *https://support.mozilla.org/en-US/kb/troubleshoot-extensions-themes-to-fix-problems