Join the AMA (Ask Me Anything) with the Firefox leadership team to celebrate Firefox 20th anniversary and discuss Firefox’s future on Mozilla Connect. Mark your calendar on Thursday, November 14, 18:00 - 20:00 UTC!

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

Thunderbird hits 100% CPU usage [inexplicably solved]

  • 2 replies
  • 1 has this problem
  • 9 views
  • Last reply by lotharyx

more options

I noticed Thunderbird hitting and maintaining 100% CPU usage recently. On Toad-Hall's advice, I tried to narrow down to a particular add-on. In this case, disabling the Provider for Google Calendar add-on appeared to stop the behavior, but re-enabling the same add-on did not cause the behavior to return, so it's not clear to me whether Provider for Google Calendar was actually causing the problem. At any rate, it's not doing it now. Maybe this'll be useful to someone else.

I noticed Thunderbird hitting and maintaining 100% CPU usage recently. On Toad-Hall's advice, I tried to narrow down to a particular add-on. In this case, disabling the Provider for Google Calendar add-on appeared to stop the behavior, but re-enabling the same add-on did not cause the behavior to return, so it's not clear to me whether Provider for Google Calendar was actually causing the problem. At any rate, it's not doing it now. Maybe this'll be useful to someone else.

Modified by lotharyx

All Replies (2)

more options

re :Thunderbird freezes or is extremely slow

You should have asked your own question. You do not have the same symptoms - when you go into Safe Mode, it resolves your issue. The person in other question has issue regardless.

Standard practise when Thunderbird safe mode works is to disable one addon, restart Thunderbird and test performance. Repeat this until you locate the addon causing the issue.


quoted: Hi, I'm having a similar problem, which seems to have started recently. My machine has 4 cores, and tbird eats up 100% of one shortly after being launched, but the UI remains responsive. For me, Safe Mode does make the problem go away, but of course I want my add-ons to be functional. Using the same log setup as MarcoZ62, the log stops dead in the middle of a line like his does. Here's my Troubleshooting Info (with account stuff redacted):

https://pastebin.com/kjWZ4uVW

(It's way too big to just dump on this thread!)

Let me know what else I can do to gather information and generally help solve this! Thanks!

more options

Apologies then. I didn’t want to create a duplicate if it was the same, but I see my error in judgment. Let me see if I can fix this question, or if not I’ll start a new proper one.