chromecast: getting 'please enable the Adobe Flash plugin in your browser settings' message

bought a HP Pavilion w adobe installed on it, i use chromecast as my browser, when trying to watch a certain site (mlb.com) i get this message

You have launched an event that is only accessible with Adobe Flash Player. To watch this event, please install the latest version. Download»

If Flash is installed, please enable the Adobe Flash plugin in your browser settings. For instructions, please click here».

yet my computer says its installed, as well as adobe, ive also allowed all to run flash and also put in the specific site to be allowed. what am i doing wrong or what do i do?

PLEASE HELP!!

[moderator: modified title to accurately reflect issue being reported]