Flash Player won't install

Am trying to install latest update on Mac (El Capitan 10.11-5) wit Google Chrome browser.  Installer downloads but when I double click to do the installation a message comes up that asks for my user id and password.  The user id dos is filled in already ( my actual name, not email address  which is my adobe id) and if I put the just-changed password in it won't take it.  No message appears to tell me what is wrong.  The box just shimmies.  Can you tell me what I am doing wrong/should do differently?