Closed Bug 1208116 Opened 9 years ago Closed 9 years ago

Thunderbird freezes/stalls when doing some IMAP operations, with Microsoft Windows Defender

Categories

(Thunderbird :: Message Reader UI, defect)

38 Branch
x86_64
Windows 8.1
defect
Not set
major

Tracking

(Not tracked)

RESOLVED INVALID

People

(Reporter: bpglueguy-mozilla, Unassigned)

Details

(Keywords: perf, Whiteboard: [antivirus: Microsoft Defender])

User Agent: Mozilla/5.0 (Windows NT 6.3; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/45.0.2454.99 Safari/537.36

Steps to reproduce:

Only doing "normal" email operations. Reading/writing emails. I do have 5 different email accounts on different servers. Three (3) of them are POP accounts, and two (2) of them are IMAP accounts.


Actual results:

The Thunderbird UI freezes/hangs/stalls in the middle of almost any operation. Windows shows (Unrersponsive) in the title bar, and I am unable to get Thunderbird to do anything for anywhere from 5 to 20 seconds.

Thunderbird is 38.2.0
Windows is Windows 8.1
Processor AMD A10-6700 APU with Radeon HD Graphics 3.69 GHz
Memory 10 GB (9.20 GB usable)
System type 64-bit, x64-based processor



Expected results:

I would not expect the UI to freeze up during any background operations.

The only "clue" I have is that this did not start until I added the two IMAP accounts. So I suspect that this has somethig to do with IMAP operations.

I did find an old bug report that indicated a similar issue that implicated Windows Search. I removed thunderbird folders from Windows Search, but it made no difference.

Please let me know what other information I can provide.
Keywords: hang
OS: Unspecified → Windows 8.1
Hardware: Unspecified → x86_64
Start *Windows'* safe mode with networking enabled
- win8 http://windows.microsoft.com/en-us/windows-8/windows-startup-settings-safe-mode
Still In Windows safe mode, start thunderbird in safe mode
- http://support.mozillamessaging.com/en-US/kb/safe-mode

Does problem go away?
Severity: normal → major
Flags: needinfo?(bpglueguy-mozilla)
Keywords: hangperf
Did both of those things, and it appears to have "fixed" the problem.

I then restarted Windows 8.1 in normal mode, but still started Thunderbird in safe mode. So far, it appears to be working as expected. My initial suspicion (at this point) is one of the add-ons I have for Thunderbird is causing the freeze-up. 

The most recent is the Lightning calendar, and the Provider for Google Calendar. I will enable the other add-ons excepting those two to try and isolate which one is causing the problem. This may take a few tries, as the freeze-up only seems to happen when sending/receiving mail on one of my IMAP accounts.
Flags: needinfo?(bpglueguy-mozilla)
The majority of the freezes appear to be coincident with (1) Downloading large numbers (>20), plus (2) Lightning 4.0.2.1, plus (3)Provider for Google Calendar 1.0.4. Some freezes would interrupt typing in an OGM, and sometimes cause weird side effects (like switching fonts in the middle of typing).

I disabled/removed Lightning and Provider for Google Calendar. This eliminated 90% of the freezes.

I still get brief pauses when downloading numerous IMAP emails, but they are not as long, and not as severe (have not seen the switching font phenomenon since removing Lightning/Provider).
OK. I was wrong. It was freezing up again this morning, and I had completely removed the calendar/Provider add-ons. So I started TB again in safe mode with all add-ons disabled. It still freezes up for periods of up to 20 seconds. Very irritating. 

The thing that's different this morning is that we were away for 5 days, and there was a bunch of incoming email on my two google/imap accounts. This makes me think that it is somehow related to the IMAP mail handling or something, as it appears to be associated with the volume of IMAP mail handling. I don't know. I did run the Windows Resource Monitor, and when the freezes occur, there is _NOT_ a lot of processing going on. What I do see is quite a lot (but not an "enormous" amount of network traffic going to "pf-in-f16.1e100.net", which appears to be an internal server owned by google (I'm guessing the actual server that is handing out at least one of my google/imap accounts).
I think I know what the issue is now. It's Windows Defender locking up the Thunderbird mail files. I found that if I turn off Windows Defender, the freezes would not occur. I then added the Thunderbird mail directories to the "excluded" list ($APPDATA\Thunderbird\Profiles). This solves the problem.

It should be published that Windows Defender should not be scanning Thunderbird mail folders/directories.
Thanks for that information.

Defender is indeed listed at https://wiki.mozilla.org/Thunderbird:Testing:Antivirus_Related_Performance_Issues
Status: UNCONFIRMED → RESOLVED
Closed: 9 years ago
Resolution: --- → INVALID
Summary: Thunderbird freezes/stalls when doing some IMAP operations → Thunderbird freezes/stalls when doing some IMAP operations, with Microsoft Windows Defender
Whiteboard: [antivirus: Microsoft Defender]
Does disabling scanning of the TB profiles directory make it a target for malware installation? If it's expected that this directory is not scanned, nefarious programs may intentionally write their payload to the Thunderbird profile directory.
(In reply to Michael Gauthier [:gauthierm] from comment #7)
> Does disabling scanning of the TB profiles directory make it a target for
> malware installation? If it's expected that this directory is not scanned,
> nefarious programs may intentionally write their payload to the Thunderbird
> profile directory.

no. And it causes many issues.  see the link in comment 6
(In reply to Wayne Mery (:wsmwk, use Needinfo for questions) from comment #8)
> (In reply to Michael Gauthier [:gauthierm] from comment #7)
> > Does disabling scanning of the TB profiles directory make it a target for
> > malware installation? If it's expected that this directory is not scanned,
> > nefarious programs may intentionally write their payload to the Thunderbird
> > profile directory.
> 
> no. And it causes many issues.  see the link in comment 6

I did read that article before posting my question -- the linked article just links to this bug report. Disabling scanning for the profile folder makes the symptoms disappear but I'm worried it makes my computer more vulnerable. Thunderbird doesn't have exclusive access to those folders on my computer.

I just had an issue with an infested Word document that came by email. Windows defender found this file in C:\Users{USER}\AppData\Local\Temp\ so maybe the profile directory is not primarily a problem. On the other hand, saved mails that seem to be safe at first and only a later virus signature lookup and identify maliscous attachments, maybe they would stay ignored.. I am still not sure, if it is safe to exclude the Thunderbird profiles..

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