Bug: Thunderbird freezing regularly with "not responding" message due to "transition from sleep to hibernate"
Status: RESOLVED
Priority: --
Resolution: INVALID
Created: 2024-10-30 17:26:49+00:00
Resolved: 2024-12-05 10:40:35+00:00

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/130.0.0.0 Safari/537.36

Steps to reproduce:

Please see the attached file...

30 Oct 2024

Why is Thunderbird persistently "not responding"?   This problem has become steadily worse over the last several months, to the extent that it has been making me think that I need to move to a different email client.

There may be some clues in   https://support.mozilla.org/eu/questions/1446914

I think I have seen other apps exhibit this "not responding" symptom as well.  But I use Thunderbird many times each day, and the problem has been getting worse for the last month or so with Thunderbird.   The link above suggests the problem may be caused by Windows Defender repeatedly scanning the Thunderbird InBox.   Whatever the cause, the cooling fan indicates increased CPU loading but it doesn't show up on Task Manager.

However I think I have found a way to avoid the problem.   Not the same as fix it however.

Several months ago, probably following one of the monthly Microsoft updates, my Win 10 laptop which was set to sleep after 30 minutes inactivity, began transitioning to hibernate after roughly 3 hours in sleep mode.   On awakening in the morning, it was essentially busy with housekeeping for at least 5 minutes, unlike awakening from sleep which left it usable after perhaps 30 seconds.   An annoyance, but bearable.   And seemingly not long after this, but not immediately, the problem with Thunderbird freezing with a "not responding" message showed up.   At first it seemed occasional.   But by this week it was happening after I looked at every 3 or 4 messages, and the not-responding delay was often 30 seconds or more.   Extremely annoying.   And this after I had taken steps to keep the InBox down to perhaps the last couple days of mail (which seemingly made absolutely no difference).

I got curious about the postings about Windows Defender scanning and re-scanning email.  It's enabled (plus MalwareBytes) on my laptop but I don't know anything about it.   So I decided to look into whether there might be a relationship with the unexpected transition from sleep to hibernate, which I definitely had not enabled.

Didn't take long to find out online that "hybrid sleep" is becoming commonplace for laptops, to extend battery life I suppose.   I was unaware of it, and don't think the setting has historically been available.   I discovered that a transition from sleep to hibernate was set for 180 minutes and I am absolutely certain that I didn't make this setting.   So I set the transition to 1440 hours (1 day) since it is almost a given that I will be using the laptop every day.  Plus I didn't know whether "never" was a valid entry for the transition time although the window would accept that word.   I also ensured that hybrid sleep was off for both battery and plugged-in modes (it was already).   So at least in theory there is no connection with a hybrid power management setting since it was already disabled.

BOTTOM LINE:   The unexplained problem with Thunderbird posting a "not responding" message and freezing for 30 seconds or so, HAS DISAPPEARED.   So it seems clear that I was blaming Thunderbird while the problem has a different cause.   Will the problem stay gone?   I don't know.   But if you are receiving other complaints about Thunderbird annoying laptop users with a "not responding" message, this note might point you in a useful direction for a fix.