1. Write in the address bar "chrome://plugins"
2. Click "details" link
3. Find the two occurrences of "Shockwave Flash"
4. Disable the item which contains the word "Chrome" in the "Location"
5. Make sure the second item is Enabled. If it's asking you to download and install any new version of flash, do it!
Video tutorial click here
If you use IE, we recommend to stop using it.