Where are you receiving this error message? Which Adobe product are you downloading? What version of Mac OS are you using?
I'm using version 10.6.8, the error message says that I have no plug in and to download adobe flash player version 188.8.131.52, and I'm receiving this message on sites i have been using for a very long time like Youtube, etc., I hope you can get me back on track.
Moving this discussion to the Installing Flash Player forum.
Is this an Intel based Mac? What browser are you using?