I am not an expert, but here is what helped me.
1. check to see if you have the latest version of the adobe flash player. You can do this by right clicking on any video on youtube, and select about Adobe flash player. there will be some numbers next to it, that is the version. click on this and you will be sent to the Adobe website where you scroll down to see a grey box which will tell you if you have the latest version or not. you can download the latest version from that site.
2. Make sure that the code you had copied and paste is correct. In other words, that all the code is copied, and there is nothing missing. at the beginning or the end of the code.
I hope this helps...