Problem with finishing install of Flash Player on a Mac. When finishing by entering the requested password, the dialog box jiggles as if the p/w is invalid. But it works in the Adobe site.

I am trying to install Flash player on my Mac. All the steps are working as they should, until the point where I am asked to enter my password. I do this, and the dialog box jiggles as through  the p/w were invalid. However, it works to sign in to the Adobe site. I just changed it to be sure and checked again.