You could be facing this problem due to one of the following reasons:
1. Cache error - This website shows you how to clear your browser cache.
2. Flash not installed - Get the latest Flash player, it's free.
3. Browser zoom - Always set the zoom level to 100% or the default setting. Zooming in can cause the game to not load properly.
4. Restart browser - In some cases, restarting your browser can fix the problem.
If the above solutions don't work, try Google's Chrome browser - Lexulous works best with Chrome as it has Flash pre-installed.
In case you're already using Chrome and the solutions mentioned are not working, please send us a screenshot along with a detailed description of the problem you're facing.