Adobe is aware of the issue in 20.0.0.235 as they temporarily disabled tab muting in Flash outside of Safari to stop crashes and hangs in that release. The beta version of 20.0.0.238 is said to fix issue but some say it does not.

my wife's computer doesn't have this problem, her mute button is working and we both have version 42.0, but my computer is missing the mute button, it was there 2 days ago and now is gone even after rebooting

rtjay said

my wife's computer doesn't have this problem, her mute button is working and we both have version 42.0, but my computer is missing the mute button, it was there 2 days ago and now is gone even after rebooting

Does her computer have the Flash Player 20.0.0.235 version or the previous version which was 19.0.0.245

My version Flash Player is 20.0.0.235, but I still don't have the mute button on the tabs. Is that the version that is supposed to fix the problem? If so, it obviously has not.

Yesterday, I had it on some tabs, but not iheart. Today, I have not seen it on any tabs.

You should still see this button on websites that use the HTML5 media player like YouTube uses by default. Only the Flash plugin is affected and needs an update from Adobe to address this issue with the mute API in the plugin.

Does anyone know when Adobe is going to get this fixed for Flash Player tabs?