This site will have limited functionality while we undergo maintenance to improve your experience. If an article doesn't solve your issue and you want to ask a question, we have our support community waiting to help you at @FirefoxSupport on Twitter and/r/firefox on Reddit.

Search Support

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

Opening a new container-tab causes Firefox to freeze and CPU usage 100%

  • 2 replies
  • 2 have this problem
  • 9 views
  • Last reply by Kohpai

more options

While opening a usual new tab (Ctrl-T or click at the plus sign) works fine, opening a new container-tab (whether using Firefox Multi-Account Containers add-on or click and hold at the plus sign) causes Firefox to freeze for almost a minute, if not longer.

When Firefox is freezing, I notice one of my 4 CPUs has 100% usage. The freezing doesn't happen all the time, just when I open multiple container-tabs (like 4 or more tabs). I'm pretty sure It's not about container-related add-ons, because I already tried disable them all (Firefox Multi-Account Containers, New container tab, and Search and Switch Containers) and It didn't help.

For now my dirty solution is to restart my laptop. Could someone help me with this?

P.S. As you can from the attached picture, the 100% usage of CPU is caused by firefox process (glowing purple).

Update: Now I can avoid this bug by opening a usual new tab with Ctrl-T and then use "Search and Switch Containers" add-on to switch to the container I desire. This gives the normal performance.

While opening a usual new tab (Ctrl-T or click at the plus sign) works fine, opening a new container-tab (whether using Firefox Multi-Account Containers add-on or click and hold at the plus sign) causes Firefox to freeze for almost a minute, if not longer. When Firefox is freezing, I notice one of my 4 CPUs has 100% usage. The freezing doesn't happen all the time, just when I open multiple container-tabs (like 4 or more tabs). I'm pretty sure It's not about container-related add-ons, because I already tried disable them all (Firefox Multi-Account Containers, New container tab, and Search and Switch Containers) and It didn't help. For now my dirty solution is to restart my laptop. Could someone help me with this? P.S. As you can from the attached picture, the 100% usage of CPU is caused by firefox process (glowing purple). Update: Now I can avoid this bug by opening a usual new tab with Ctrl-T and then use "Search and Switch Containers" add-on to switch to the container I desire. This gives the normal performance.
Attached screenshots

Modified by Kohpai

All Replies (2)

more options

(whether using Firefox Multi-Account Containers add-on or click and hold at the plus sign) causes Firefox to freeze for almost a minute, if not longer.

Is this a FF program or a Addon?

more options

WestEnd said

(whether using Firefox Multi-Account Containers add-on or click and hold at the plus sign) causes Firefox to freeze for almost a minute, if not longer. Is this a FF program or a Addon?

Thank you for your reply!

Multi-Account Containers is a new feature on Firefox. But there is also an official add-on with the same name which helps users to use this feature easier. The one I was talking about is an add-on.

P.S. What do you mean by "FF program", btw? You mean Firefox, the browser, itself; or something else?