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

Anyone else noticing Firefox add-ons going haywire with Big Sur (11.5)?

  • No replies
  • 1 has this problem
  • Last reply by Bithiah

more options

I'm not necessarily looking for a solution, but curious if others are seeing similar issues!

A couple years ago I switched from Google Chrome to Firefox because Chrome was a notorious memory hog and kept making my Macbook freak out (i.e., hang, crash, fan acceleration). But after I upgraded to Big Sur 11.5 a few weeks ago, my Macbook started freaking out again, even with Firefox. Here are some things I suspect are causes:

  • AdBlocker Ultimate add-on. Every now and then my fan would go nuts, the add-on extensions in the upper right of my browser would glitch, and Firefox would hang (tabs refuse to load, etc) for about 30 seconds. Once I turned it off my computer has been just fine.
  • Dark Reader add-on. Same phenotype as AdBlocker.
  • My caps lock key?? This one is super weird. I noticed that when I had the above two add-ons enabled, hitting my caps lock key would commence computer freak-outs.

Anyone else seeing this? If so, what are add-ons you'd recommend that function similarly to AdBlocker and Dark Reader?

All Replies (1)

more options

Hi there!

I have recently updated my iMac to Big Sur and I have no problems with Firefox or Chrome. Because of the Big Sur update there have been a lot of talk about long download times, lag, issues with first and third-party apps including Box Drive, iMessage issues, Wi-Fi problems, Bluetooth problems, lockups, freezes, and crashes.

And it doesn't work very well with older apple devices. My iMac (Retina 4K, 21.5-inch, 2017) was very exposed to this new update so i decided to update till all the bugs and issues were mostly fixed. And now I have no problem.

I would highly recommend Adguard ( in replace for AdBlocker. I use Adguard all the time and I just needed to update AdGuard in order to work with Big Sur.

Hope I helped!

Kind regards,



Ask a question

You must log in to your account to reply to posts. Please start a new question, if you do not have an account yet.