Bug: UI randomly freezes up to 30 seconds (not responding) while downloading new mail or clicking emails
Status: UNCONFIRMED
Priority: --
Created: 2024-12-17 23:35:20+00:00
Resolved: 2025-02-26 19:42:00+00:00

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/131.0.0.0 Safari/537.36

Steps to reproduce:

1. Click download mail button to start syncing IMAP
2. Click on an email message or anything really


Actual results:

The UI freezes, windows says "Thunderbird not responding". Sometimes for several seconds to 30 seconds. It's totally random when it happens, not sure if it's caused by downloading new mail or not.

  Application Basics

    Name: Thunderbird
    Version: 128.5.2esr
    Build ID: 20241210220830
    Distribution ID:

    Update Channel: esr
    User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:128.0) Gecko/20100101 Thunderbird/128.5.2
    OS: Windows_NT 10.0 19045
    OS Theme:

    Launcher Process: Enabled
    Multiprocess Windows: 0/0
    Fission Windows: 0/0
              Enabled by default
    Remote Processes: 3
    Enterprise Policies: Inactive
    Google Location Service Key: Missing
    Google Safebrowsing Key: Missing
    Mozilla Location Service Key: Missing
    Safe Mode: true
    Memory Size (RAM): 11.9 GB
    Disk Space Available: 55.7 GB

  Mail and News Accounts
    account1:
      INCOMING: account1, , (imap) imap.ionos.com:993, 3, passwordCleartext
      OUTGOING: , smtp.ionos.com:465, 3, passwordCleartext, true

    account2:
      INCOMING: account2, , (none) Local Folders, plain, passwordCleartext

    account3:
      INCOMING: account3, , (imap) imap.gmail.com:993, 3, OAuth2
      OUTGOING: , smtp.gmail.com:465, 3, OAuth2, true

    account4:
      INCOMING: account4, , (imap) imap.gmail.com:993, 3, OAuth2
      OUTGOING: , smtp.gmail.com:465, 3, OAuth2, true

  Libraries

      Library
      Status
      Expected minimum version
      Version in use
      Path

        RNP (OpenPGP)
        OK
        0.17.1
        0.17.1.MZLA.128.5.2esr.botan
        C:\Program Files\Mozilla Thunderbird\rnp.dll

        OTR
        Failed to load. OTR chat encryption will not work.
        -
        -
        -

  Calendar Settings

    Home

      Name
      Value

      Name:
      Type: storage
      Disabled: true
      Username:
      URI:
      Refresh Interval:
      Read-only:
      Suppress Alarms:
      Cache Enabled:
      iMIP Identity: id1
      iMIP Disabled:
      iMIP Account:
      Organizer Id:
      Force Email Scheduling:
      Popup Alarms Supported:
      Alarms on Invitation Supported:
      Max Alarms Per Event:
      Attachment Supported:
      Max Categories:
      Privacy State Supported:
      Priority Supported: true
      Event Supported:
      Task Supported:
      Local Time Supported:
      UTC/GMT Supported:
      Auto-Scheduling Supported:

  Crash Reports for the Last 3 Days

  Remote Processes

    Type: Count

      Isolated Web Content: 1
      GPU: 1
      RDD: 1

  Add-ons

      Name
      Type
      Version
      Enabled
      ID

        Amazon.com
        extension
        1.1
        true
        amazondotcom@search.mozilla.org

        Bing
        extension
        1.0
        true
        bing@search.mozilla.org

        DuckDuckGo
        extension
        1.0
        true
        ddg@search.mozilla.org

        Google
        extension
        1.0
        true
        google@search.mozilla.org

        Wikipedia (en)
        extension
        1.0
        true
        wikipedia@search.mozilla.org

        System theme — auto
        theme
        1.3
        true
        default-theme@mozilla.org

        Dark
        theme
        1.3
        false
        thunderbird-compact-dark@mozilla.org

        Light
        theme
        1.3
        false
        thunderbird-compact-light@mozilla.org

  Security Software

    Type: Name

      Antivirus: Microsoft Defender Antivirus
      Antispyware:
      Firewall: Windows Firewall

  Legacy User Stylesheets

    Active: false
    Stylesheets: No stylesheets found

  Graphics

      Features
      Compositing: WebRender (Software)
      Font Visibility Debug Info: Windows Platform
      Asynchronous Pan/Zoom: wheel input enabled; scrollbar drag enabled; keyboard enabled; autoscroll enabled; smooth pinch-zoom enabled
      WebGL 1 Driver WSI Info: -
      WebGL 1 Driver Renderer: WebGL is currently disabled.
      WebGL 1 Driver Version: -
      WebGL 1 Driver Extensions: -
      WebGL 1 Extensions: -
      WebGL 2 Driver WSI Info: -
      WebGL 2 Driver Renderer: WebGL is currently disabled.
      WebGL 2 Driver Version: -
      WebGL 2 Driver Extensions: -
      WebGL 2 Extensions: -
      Target Frame Rate: 60
      DirectWrite: true (10.0.19041.4355)

      GPU #1
      Active: Yes
      Description: NVIDIA GeForce RTX 2060
      Vendor ID: 0x10de
      Device ID: 0x1f11
      Driver Version: 31.0.15.1640
      Driver Date: 6-6-2022
      Drivers: C:\Windows\System32\DriverStore\FileRepository\nvlti.inf_amd64_684a7b4cdb809f6b\nvldumdx.dll,C:\Windows\System32\DriverStore\FileRepository\nvlti.inf_amd64_684a7b4cdb809f6b\nvldumdx.dll,C:\Windows\System32\DriverStore\FileRepository\nvlti.inf_amd64_684a7b4cdb809f6b\nvldumdx.dll,C:\Windows\System32\DriverStore\FileRepository\nvlti.inf_amd64_684a7b4cdb809f6b\nvldumdx.dll C:\Windows\System32\DriverStore\FileRepository\nvlti.inf_amd64_684a7b4cdb809f6b\nvldumd.dll,C:\Windows\System32\DriverStore\FileRepository\nvlti.inf_amd64_684a7b4cdb809f6b\nvldumd.dll,C:\Windows\System32\DriverStore\FileRepository\nvlti.inf_amd64_684a7b4cdb809f6b\nvldumd.dll,C:\Windows\System32\DriverStore\FileRepository\nvlti.inf_amd64_684a7b4cdb809f6b\nvldumd.dll
      Subsys ID: 3ffd17aa
      RAM: 6144

      GPU #2
      Active: No
      RAM: 0

      Diagnostics
      AzureCanvasBackend: skia
      AzureCanvasBackend (UI Process): skia
      AzureContentBackend: skia
      AzureContentBackend (UI Process): skia
      AzureFallbackCanvasBackend (UI Process): skia
      CMSOutputProfile: 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
      Display0: 1920x1080@60Hz scales:1.000000|1.250000
      DisplayCount: 1
      HardwareStretching: both=1 window-only=0 full-screen-only=0 none=0 error=0
      GPUProcessPid: 2352
      Window Device Pixel Ratios: 1.25
      ClearType Parameters: Gamma: 1.8 Pixel Structure: RGB ClearType Level: 100 Enhanced Contrast: 50
      Font Visibility Debug Info: Windows Platform
      WebGPU Default Adapter: [object Object]
      WebGPU Fallback Adapter: [object Object]

      Decision Log
      HW_COMPOSITING: available by defaultblocked by runtime: Acceleration blocked by safe-mode
      D3D11_COMPOSITING: unavailable by default: Hardware compositing is disabled
      DIRECT2D: unavailable by default: Direct2D requires Direct3D 11 compositing
      D3D11_HW_ANGLE: unavailable by default: D3D11 compositing is disableddisabled by env: D3D11 compositing is disabled
      GPU_PROCESS: available by default
      WEBRENDER: available by defaultunavailable-in-safe-mode by runtime: Safe-mode is enabled
      WEBRENDER_COMPOSITOR: available by defaultunavailable by runtime: No DirectComposition usage
      WEBRENDER_PARTIAL: available by default
      WEBRENDER_SHADER_CACHE: available by defaultunavailable by runtime: WebRender disabled
      WEBRENDER_OPTIMIZED_SHADERS: available by defaultunavailable by runtime: WebRender disabled
      WEBRENDER_ANGLE: available by defaultunavailable-no-angle by runtime: ANGLE is disabled
      WEBRENDER_DCOMP_PRESENT: available by defaultunavailable by runtime: Requires ANGLE
      WEBRENDER_SCISSORED_CACHE_CLEARS: available by default
      WEBGPU: available by defaultblocked by runtime: WebGPU cannot be enabled in release or beta
      WINDOW_OCCLUSION: available by default
      VP8_HW_DECODE: available by default
      VP9_HW_DECODE: available by default
      REUSE_DECODER_DEVICE: available by default
      BACKDROP_FILTER: available by default
      CANVAS_RENDERER_THREAD: available by default
      ACCELERATED_CANVAS2D: disabled by default: Disabled by defaultblocked by env: Disabled by Software WebRenderfailed by runtime: Disabled with non-zero canvas worker threads
      REMOTE_CANVAS: available by default

    Crash Guard Disabled Features

    Workarounds

    Failure Log

  Media

      Audio Backend: wasapi
      Max Channels: 2
      Preferred Sample Rate: 48000
      Roundtrip latency (standard deviation): NaNms (NaN)

      Output Devices

        Name
        Group
        Vendor
        State
        Preferred
        Format
        Channels
        Rate
        Latency

        VZ27A (NVIDIA High Definition Audio)
        HDAUDIO\FUNC_01&VEN_10DE&DEV_0093&SUBSYS_17AA3FFD&REV_1001\5&7ac6f31&0&0001
        Unplugged
        None
        default: F32LE, support: S16LE F32LE
        2
        default: 48000, support: 48000 - 48000
        0 - 0

        Speakers (Realtek(R) Audio)
        HDAUDIO\FUNC_01&VEN_10EC&DEV_0257&SUBSYS_17AA3810&REV_1000\4&2eb7f11b&0&0001
        Enabled
        All
        default: F32LE, support: S16LE F32LE
        2
        default: 48000, support: 48000 - 48000
        144 - 480

        Speakers (Steam Streaming Microphone)
        ROOT\SteamStreamingMicrophone\0000
        Enabled
        None
        default: F32LE, support: S16LE F32LE
        2
        default: 48000, support: 48000 - 48000
        144 - 480

        Speakers (Steam Streaming Speakers)
        ROOT\SteamStreamingSpeakers\0000
        Enabled
        None
        default: F32LE, support: S16LE F32LE
        2
        default: 48000, support: 48000 - 48000
        144 - 480

      Input Devices

        Name
        Group
        Vendor
        State
        Preferred
        Format
        Channels
        Rate
        Latency

        Microphone Array (Realtek(R) Audio)
        HDAUDIO\FUNC_01&VEN_10EC&DEV_0257&SUBSYS_17AA3810&REV_1000\4&2eb7f11b&0&0001
        Enabled
        All
        default: F32LE, support: S16LE F32LE
        2
        default: 48000, support: 48000 - 48000
        144 - 480

        Microphone (Steam Streaming Microphone)
        ROOT\SteamStreamingMicrophone\0000
        Enabled
        None
        default: F32LE, support: S16LE F32LE
        1
        default: 44100, support: 44100 - 44100
        133 - 441

      Media Capabilities

      Enumerate database

  Environment Variables

    MOZ_APP_RESTART: 1
    MOZ_CRASHREPORTER_DATA_DIRECTORY: C:\Users\micro\AppData\Roaming\Thunderbird\Crash Reports
    MOZ_CRASHREPORTER_EVENTS_DIRECTORY: C:\Users\micro\AppData\Roaming\Thunderbird\Profiles\amip2brk.default-release\crashes\events
    MOZ_CRASHREPORTER_PING_DIRECTORY: C:\Users\micro\AppData\Roaming\Thunderbird\Pending Pings
    MOZ_CRASHREPORTER_STRINGS_OVERRIDE: C:\Program Files\Mozilla Thunderbird\crashreporter-override.ini
    MOZ_LAUNCHER_PROCESS: 1

  Important Modified Preferences

    browser.search.region: US
    extensions.lastAppVersion: 128.5.2
    font.internaluseonly.changed: false
    gfx.crash-guard.status.wmfvpxvideo: 2
    gfx.crash-guard.wmfvpxvideo.appVersion: 91.13.1
    gfx.crash-guard.wmfvpxvideo.deviceID: 0x1f11
    gfx.crash-guard.wmfvpxvideo.driverVersion: 31.0.15.1640
    idle.lastDailyNotification: 1734155487
    media.gmp.storage.version.observed: 1
    media.hardware-video-decoding.failed: false
    network.trr.blocklist_cleanup_done: true
    places.database.lastMaintenance: 1733682859
    privacy.bounceTrackingProtection.hasMigratedUserActivationData: true
    privacy.purge_trackers.date_in_cookie_database: 0
    security.sandbox.content.tempDirSuffix: {372d64cb-fed4-4875-985d-9f713f0e422e}
    storage.vacuum.last.content-prefs.sqlite: 1734155490
    storage.vacuum.last.index: 1
    storage.vacuum.last.places.sqlite: 1733682857
    ui.osk.debug.keyboardDisplayReason: IKPOS: Touch screen not found.

  Important Locked Preferences

  fission.autostart.session: true

  Places Database

  Accessibility

    Activated: false
    Prevent Accessibility: 0
    Accessible Handler Used:
    Accessibility Instantiator:

  Library Versions

      Expected minimum version
      Version in use

      NSPR
      4.35
      4.35

      NSS
      3.101.1
      3.101.1

      NSSSMIME
      3.101.1
      3.101.1

      NSSSSL
      3.101.1
      3.101.1

      NSSUTIL
      3.101.1
      3.101.1

  Sandbox

    Content Process Sandbox Level: 0
    Effective Content Process Sandbox Level: 1
    Win32k Lockdown State for Content Process: Win32k Lockdown disabled -- Running in Safe Mode
    GPU Process Sandbox Level: 1

  Startup Cache

    Disk Cache Path: C:\Users\micro\AppData\Local\Thunderbird\Profiles\amip2brk.default-release\startupCache\startupCache.8.little
    Ignore Disk Cache: false
    Found Disk Cache on Init: false
    Wrote to Disk Cache: false

  Internationalization & Localization

      Application Settings
      Requested Locales: ["en-US"]
      Available Locales: ["en-US"]
      App Locales: ["en-US"]
      Regional Preferences: ["en-US"]
      Default Locale: "en-US"

      Operating System
      System Locales: ["en-US"]
      Regional Preferences: ["en-US"]

  Remote Debugging (Chromium Protocol)

    Accepting Connections:
    URL:

  Printing

  Modified print settings

  print_printer: HP5A85BB (HP Photosmart 6520 series)


Expected results:

All download/sync/IO operations should happen off the UI thread.