Mozilla Monitor website will be down for 2 hours starting 5/20/2025 at 6 AM PT. Visit our status site for updates.

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

This thread was closed and archived. Please ask a new question if you need help.

after exit firefox keeps running and opens 13 plugincontainers

  • 2 replies
  • 2 have this problem
  • 1 view
  • Last reply by SuMo Bot

After exiting firefox the firefox window closes but the firefox task keeps running. If I watch what is happening in process explorer's task manager I see firefox and slowly a series of 13 or so plugincontainers open beneath it. Then is just sits there.

I tried restarting with all addons disabled. But the problem continued unchanged.

I tried uninstalling firefox and then reinstalling firefox. But the problem continues unchanged.

After exiting firefox the firefox window closes but the firefox task keeps running. If I watch what is happening in process explorer's task manager I see firefox and slowly a series of 13 or so plugincontainers open beneath it. Then is just sits there. I tried restarting with all addons disabled. But the problem continued unchanged. I tried uninstalling firefox and then reinstalling firefox. But the problem continues unchanged.

Chosen solution

That can happen in the use Clear Recent History to clear the cookies when you close Firefox.
Exclude the cookies from "Clear Recent History" to see if that helps.


If you use "Clear Recent History" to clear the cookies then Firefox also tries to clear the cookies from plugins like Flash (LSO) and starts a plugin-container process for each plugin and that can add extra time and can cause an unresponsive script error to appear.
Make sure that all plugins are up to date.

Read this answer in context 👍 0

All Replies (3)

Chosen Solution

That can happen in the use Clear Recent History to clear the cookies when you close Firefox.
Exclude the cookies from "Clear Recent History" to see if that helps.


If you use "Clear Recent History" to clear the cookies then Firefox also tries to clear the cookies from plugins like Flash (LSO) and starts a plugin-container process for each plugin and that can add extra time and can cause an unresponsive script error to appear.
Make sure that all plugins are up to date.

I was able to stop the plugincontainers from opening and get a faster close of firefox by setting options to never remember history. Thanks for your help.

This question has been locked because the original author has deleted their account. While you can no longer post new replies, the existing content remains available for reference.