How to Disable Plugin Hang UI in Mozilla Firefox

Mozilla Firefox runs all the plugins in their own processes by default through the out-of-process (OOP) technology. This is done to prevent any of those plugins crashing Firefox process in case those plugins hang up. Because the plugins run in their own process, they do not affect the working of Firefox browser even if they crash. This is a great feature that allows you to keep working with Firefox when one or more of the plugins crash in browser windows. But one of the annoying features that come along with this is the Unresponsive Plugin message window using the Plugin Hang UI.

When a plugin becomes unresponsive for some time, the out-of-process technology kills them after a few seconds. But during this time, you are shown an unresponsive plugin message with options to stop or continue with the offending plugin.

Disable Firefox Plugins Hang UI

If you do not want to see this message and want Firefox to handle killing of the unresponsive plugin automatically, then you can follow these steps:

  1. Type about:config in Firefox address bar and press Enter.
  2. Click on the button labeled I’ll be careful, I promise! in the warning message window.
  3. This will open a list of settings for Firefox browser. To narrow down the settings we want, type ipc.plugins.hang in the Search box.
  4. Double-click on the setting named dom.ipc.plugins.hangUITimeoutSecs and change its value from 11 to 0.Disable Firefox Plugins Hang UI
  5. Restart Firefox web browser.

From now on Firefox will not show you any unresponsive plugins messages. Instead it will wait and kill the unresponsive plugins automatically after a few seconds on its own without bothering you.