For Windows, see Flash Player installation problems (Windows).
For Mac OS, see Flash Player installation problems (Mac OS).
If another player installed on your computer is set as the default player, information may not get to your Flash Player. Make Flash Player the default player and try to watch the video again.
Make sure that the security level is not set to High or to a custom level that doesn't allow viewing of ActiveX controls. Typically, the default security level (medium) allows you to view Flash content. For a custom level, ensure that both Download Signed ActiveX Controls and Run ActiveX Controls And Plug-ins are set to Prompt. For example, in Internet Explorer:
Some Internet utilities function similar to a firewall and can restrict viewing of ActiveX controls. In some cases, they block Flash Player content. Ensure that firewall or utility settings are set to allow ActiveX controls, Flash Player content, and the website you are visiting.