Videos don't start: Mac OS-X 10.7.5; Flash Player 18.0.0.160

MacBook Pro, Mac OS-X 10.7.5; Safari 6.1.6; Firefox 38.0.5; Chrome 40.0.2214.94; Flash Player 18.0.0.160. Videos don't start; Ads when at the beginning of a video don't count down from 5 seconds. Tried videos from YouTube, BBC, CNN. In the case of Safari, error message "An error occurred. Please try again later. Learn More" appears. No error messages appear with FireFox or Chrome--videos just don't start. Already tried Flash Player Uninstall (using 18.0.0.160), then closing all browsers, fresh installing Flash Player 18.0.0.160, then restarting MacBook Pro, opening browsers--no change. Fresh installed Java 8 version 45 (jre-8u45-macosx-x64) with no change. Verified FlashPlayer was enabled in all browsers. I do see moving cloud animation at https://helpx.adobe.com/flash-player.html in all three browsers. Any suggestions?