2025-09-28
Anki 25.09 crashes when syncing twice with the Habitica addon enabled. Syncing with the addon disabled works normally. This first started around ~two weeks ago, as that is when I saved a crash dump. I am not able to get a Python-level traceback with Visual Studio 2022 as uv does not provide debug builds of Python, which would provide debugging symbols necessary for mixed-mode Python debugging.
I think the bug is either a bug in Qt6Widgets or caused by my somewhat out-of-date graphics driver.
Anki heap corruption reproducer:
- Study some cards
- Restart Anki (with auto-sync off)
- Sync
- Click no on “New reviews found. Sync with Habitica?”
- Sync again, clicking No each time.
- Crashes with heap corruption
Reproducibility:
Happens every time unless I have the Habitica addon disabled. Sometimes I have to repeat steps 3 and 4.
Affected versions:
Release Anki 25.09.2 from ankitects/Anki/releases on GitHub
Development Anki 25.09.2-16-g72d83ffc9
Graphics stuff:
The crash occurs with all of the following rendering APIs: Direct3D, OpenGL, Vulkan, and even Software rendering. I had Direct3D enabled when I first noticed the crash.
Driver version: 577.00 (I should probably update to 581.29 soon)
Nvidia GTX 1060, Intel HD 630
Computer model: MSI GS63 Stealth 8RE
OS: Windows 10 22H2 19045t.6396 x86_64
Addon bug detector:
Detection completed! :-)
Detected add-on:
['1758045507', 'Anki Habitica for 21']
Exit Detector Mode. Press OK to restart Anki and restore the add-ons to the state before using DetectorMode.
Sync settings:
- Synchronize audio and images too
- Automatically sync on profile open/close
- Periodically sync media
- On next sync, force changes in one direction
Network timeout: 30 seconds.
Exact error is as follows:
An unhandled win32 exception has occurred in [13616] pythonw.exe
and when debugging in VS 2022 17.14.16:
Exception Unhandled:
Unhandled exception at 0x00007FFBA012F3C9 (ntdll.dll) in pythonw.exe: 0xC0000374: A heap has been corrupted (parameters: 0x00007FFBA01997F0).
Anki version and addons
Anki 25.09.2 (3890e12c) (ao)
Python 3.13.5 Qt 6.9.1 PyQt 6.9.1
Platform: Windows-10-10.0.19045-SP0
===Add-ons (active)===
(add-on provided name [Add-on folder, installed at, version, is config changed])
'' ['tag2radiostation', 0, 'None', mod]
AJT Card Management Reset Learn and Grade cards from the Anki Browser ['1021636467', 2025-09-13T23:07, 'None', '']
Accumulated Retention Graph FSRS ETK ['1971437351', 2025-07-01T01:43, 'None', '']
Add a tag to notes with missing media ['2027876532', 2022-06-04T17:28, 'None', '']
Anki Habitica for 21 ['1758045507', 2024-09-03T03:47, 'None', '']
Anki Leaderboard - Compete with friends to boost motivation Custom by Shige ['175794613', 2025-05-14T15:23, 'None', mod]
Anki Preview Reloader ['571150035', 2025-01-31T12:22, '1.0.2', '']
AnkiConnect ['2055492159', 2025-09-06T10:03, 'None', '']
AnkiCord - Discord Rich Presence Customized by Shige ['933207442', 2025-03-18T10:59, 'None', '']
AnkiMorphs ['472573498', 2025-09-24T09:51, 'None', mod]
AnkiRestart - Quick Anki Rebooter for Customize Develop Created by Shige ['237169833', 2025-06-21T19:33, 'None', mod]
AnkiWebView Inspector ['31746032', 2023-06-27T12:26, 'None', '']
AwesomeTTS - Add speech to your flashcards ['1436550454', 2025-08-15T18:02, 'None', mod]
Batch Editing ['291119185', 2023-10-25T17:38, 'None', '']
Break Timer - After 10 cards take a 3 minute break Created by Shige ['174058935', 2025-05-14T17:20, 'None', mod]
Cloze Hide All ['1709973686', 2025-09-03T06:38, '25.9.3i145', mod]
Cloze Overlapper for Anki 21 ['109531687', 2021-01-11T19:12, 'None', '']
Color Confirmation ['1084228676', 2024-01-06T01:55, 'None', mod]
Customize Keyboard Shortcuts ['24411424', 2023-11-01T02:17, 'None', mod]
Enhance main window ['877182321', 2023-10-22T13:28, 'None', mod]
FSRS Helper Postpone Advance Load Balance Easy Days Disperse Siblings ['759844606', 2025-09-18T19:10, 'None', mod]
Fix invalid card IDs ['196231552', 2021-11-25T17:33, 'None', '']
Image Occlusion Enhanced ['1374772155', 2022-04-09T00:15, 'None', '']
Korean Support ['1336389630', 2025-06-16T14:25, 'None', mod]
OpenInExternalEditorRenameDuplicate for ImageAudioVideo WinLinux ['1560623518', 2023-03-19T10:33, 'None', '']
Progress Bar ['2091361802', 2018-02-08T16:03, 'None', '']
Progress Bar cards done cards left secondscard time spentleft and ETA ['1097423555', 2023-10-02T01:05, 'None', mod]
Progress bar Actual ['1882716549', 2025-05-17T23:31, 'None', '']
Review Heatmap ['1771074083', 2022-06-29T18:43, 'None', '']
Searching PDF Reading and Note-Taking in Add Dialog Fixed by Shige ['1250212877', 2025-07-17T11:08, 'None', mod]
Tags are mandatory to add a card ['1116519045', 2020-05-02T03:17, 'None', '']
add-on dialog searchfilter bar ['561945101', 2023-10-18T09:22, 'None', '']
extended editor for field for tables searchreplace ['805891399', 2025-07-06T03:41, 'None', mod]
===IDs of active AnkiWeb add-ons===
1021636467 1084228676 109531687 1097423555 1116519045 1250212877 1336389630 1374772155 1436550454 1560623518 1709973686 174058935 175794613 1758045507 1771074083 1882716549 196231552 1971437351 2027876532 2055492159 2091361802 237169833 24411424 291119185 31746032 472573498 561945101 571150035 759844606 805891399 877182321 933207442
===Add-ons (inactive)===
(add-on provided name [Add-on folder, installed at, version, is config changed])
'' ['Quantified_Self_add-on_-_export_your_review_log_-_v02', 0, 'None', '']
'' ['Removes_Empty_Note_Types', 0, 'None', '']
'' ['anki-addon-glossary', 0, 'None', '']
'' ['anki-enhance-main-window', 0, 'None', mod]
'' ['anki-quick-easy', 0, 'None', '']
'' ['awesometts-anki-addon', 0, 'None', '']
'' ['deadline', 0, 'None', '']
'' ['deck_name_in_title', 0, 'None', '']
'' ['gCalEventPush', 0, 'None', '']
'' ['main_fullscreen', 0, 'None', '']
'' ['remaining_time', 0, 'None', '']
Add Hyperlink ['318752047', 2023-06-18T04:39, 'None', '']
Add Table ['1237621971', 2023-06-18T04:37, 'None', mod]
Additional Card Fields Fork for 21 ['744725736', 2022-10-23T03:10, 'None', mod]
Anki Fanfare GamificationFeedback ['2073603704', 2018-12-14T06:42, 'None', mod]
Anki Habitica formerly Anki HRPG ['954979168', 2019-05-28T00:33, 'None', '']
AnkiCollab ['315336869', 2019-01-17T23:09, 'None', mod]
AnkiDiscord - Discord integration for Anki Updated 2025 ['1133851639', 2025-08-15T22:39, 'None', '']
Another Retreat ['1481634779', 2018-02-08T16:16, 'None', '']
Auto Ease Factor ['1672712021', 2021-03-21T11:11, 'None', mod]
Auto Markdown ['1030875226', 2019-06-18T02:03, 'None', '']
Backup Key ['1790131139', 2019-03-06T12:24, 'None', '']
Chinese Companion - frequency sort HSK suspend heisig support and more ['2129668097', 2019-05-20T01:02, 'None', '']
Chinese Support Redux ['839350950', 2018-02-17T11:55, 'None', mod]
Clean the default deck ['683170394', 2018-12-09T00:31, 'None', '']
Content Injector ['166455199', 2020-09-03T09:08, 'None', '']
Convert Subdecks to Tag Hierarchy ['1172858842', 2023-02-07T10:15, 'None', '']
Create Filtered Deck from the Browser ['861263371', 2018-02-08T16:20, 'None', '']
CrowdAnki JSON exportimport Edit history Collaborate on deck creation ['1788670778', 2023-10-30T11:57, 'None', '']
Custom Styles font color background colour classes ['1899278645', 2023-02-25T06:28, 'None', '']
Deck Stats ['1421528223', 2021-06-12T06:30, 'None', '']
Delay siblings ['1369579727', 2022-06-03T16:05, 'None', '']
DrawingPad ['370778248', 2023-09-16T12:49, 'None', '']
Ease Factor Histogram ['494944895', 2019-05-01T20:31, 'None', '']
Echelon - Improved Hierarchical Tags for Anki 21 - Unsupported ['829533913', 2019-11-17T15:54, 'None', '']
Edit Field During Review ['1020366288', 2022-08-29T12:38, 'None', mod]
Edit cards template with python and a domain specific language ['1159566613', 2020-03-09T00:57, 'None', '']
Export Cards As Text ['1112021968', 2021-07-08T00:57, 'None', '']
Export cards selected in the Browser ['1983204951', 2019-04-23T16:45, 'None', '']
Extended Card Stats During Review ['1008566916', 2024-02-26T11:07, 'None', '']
Fast cards reposition ['544982740', 2021-09-19T06:51, 'None', '']
Fastbar another toolbar for Anki 21 beta ['1955978390', 2018-02-08T16:09, 'None', '']
Field History ['1247884413', 2019-01-10T12:18, 'None', '']
Frozen Fields ['516643804', 2020-02-29T20:12, 'None', '']
Full Screen Toggle ['1612375712', 2019-01-09T21:50, 'None', '']
HTML Window source ['1214415810', 2020-02-18T05:20, 'None', '']
Highlight Search Results in the Browser ['225180905', 2023-10-21T12:17, 'None', '']
HoochieBaby Queue Controller Day-Lrn Q ['1847358755', 2020-11-22T18:54, 'None', '']
HoochieMama Randomize Rev Queue ['1460733408', 2020-06-03T06:17, 'None', '']
HoochiePapa Randomize New Queue ['1173108619', 2020-04-24T20:17, 'None', '']
Ignore accents in browser search ['1924690148', 2020-11-28T03:29, 'None', '']
Improved Quizlet to Anki 21 Importer ['538351043', 2020-11-14T18:16, 'None', '']
Incremental Reading v4103 ['935264945', 2019-04-21T21:09, 'None', '']
Japanese Support ['3918629684', 2023-10-18T20:13, 'None', mod]
Kanji Grid ['909972618', 2019-01-09T17:58, 'None', '']
Knockout Deck Subset Learning ['899747926', 2019-04-03T00:35, 'None', '']
LPCG LyricsPoetry Cloze Generator ['2084557901', 2023-12-06T19:43, 'None', '']
Leaderboard ['41708974', 2023-01-15T02:53, 'None', mod]
Life Drain ['715575551', 2024-12-02T22:44, 'None', '']
Load Balanced Scheduler ['208879074', 2018-10-11T01:20, 'None', '']
MemoBeam ['1809412029', 2021-04-01T08:34, 'None', '']
Mental Pause No bonus for being late ['1707633456', 2020-04-17T00:05, 'None', '']
More Overview Stats 21 ['738807903', 2025-02-17T13:14, 'None', '']
MorphMan for Anki 21 ['900801631', 2023-08-17T19:37, 'None', '']
Move Stats and Sync buttons to the right ['1610151176', 2018-12-20T09:07, 'None', '']
Night Mode ['1496166067', 2019-04-20T15:04, 'None', '']
Note Size - sort notes by size and see collection size ['1188705668', 2025-04-19T06:41, 'v2.10.0', '']
Obtain a beautiful readable and debuggable database for anki ['1585491271', 2019-02-20T07:42, 'None', '']
Opening the same window multiple time ['354407385', 2023-11-04T18:59, 'None', '']
Pretzel Logic Retention Benchmarking ['1168065472', 2020-04-24T20:13, 'None', '']
Progress Graphs and Stats for Learned and Matured Cards ['266436365', 2020-03-28T23:26, 'None', '']
Rebuild All Empty All for Anki 21 ['1810938259', 2018-07-19T21:40, 'None', '']
Refocus Card when Reviewing 21 ['1642550423', 2018-10-12T16:20, 'None', '']
Replay buttons on card ['498789867', 2018-02-08T15:54, 'None', '']
Review Heatmap ['review_heatmap', 2020-04-30T06:23, 'None', '']
Right Hand Reviews jkl ['1212877655', 2019-03-18T18:19, 'None', '']
Ruzu Pop-ups ['1736169259', 2024-12-19T08:19, 'v0.0.5', mod]
Search and Replace Tags ['138501288', 2018-02-08T16:03, 'None', '']
Searching PDF Reading Note-Taking in Add Dialog ['1781298089', 2022-08-15T00:22, 'None', '']
Slackers Delight PostponeDefer Button ['880824023', 2020-02-26T11:09, 'None', '']
Speed Focus Mode auto-alert auto-reveal auto-answer ['1046608507', 2022-12-16T03:24, 'None', '']
Stats Overview Pie Graph with Distinct Learning and-or Relearning Sections ['1828603731', 2019-05-26T02:06, 'None', mod]
Syntax Highlighting for Code ['1463041493', 2019-04-04T22:59, 'None', '']
Touch Screen - draw and write on your cards ['1631622775', 2019-04-20T15:04, 'None', '']
Touch Wood Show New Cards Left Hint ['1498273991', 2020-04-03T21:37, 'None', '']
True Retention ['613684242', 2018-02-08T15:55, 'None', '']
True Retention by Card Maturity ['923360400', 2019-01-13T22:45, 'None', '']
Unstable See Description Pull from Duolingo ['557761805', 2023-03-24T12:17, 'None', '']
Zoom 21 ['1846592880', 2020-01-12T09:26, 'None', '']
maobi - Chinese Hanzi Writing Quizzes in Anki v0 6 0 ['931477147', 2024-07-27T08:36, 'None', mod]
Backtrace
Process ID: 13516 (45 threads)
Current thread: 11616 Worker Thread CrBrowserMain
Backtrace
> ntdll.dll!00007ffba012f3c9() Unknown
> ntdll.dll!00007ffba012f393() Unknown
> ntdll.dll!00007ffba0138112() Unknown
> ntdll.dll!00007ffba01383fa() Unknown
> ntdll.dll!00007ffba013e081() Unknown
> ntdll.dll!00007ffba0055b43() Unknown
> ntdll.dll!00007ffba00547b1() Unknown
> ucrtbase.dll!00007ffb9d6df05b() Unknown
> Qt6Widgets.dll!00007ffaab73eb9e() Unknown
> Qt6Core.dll!00007ffab6920800() Unknown
> Qt6Widgets.dll!00007ffaab50f8f0() Unknown
> QtWidgets.pyd!00007ffaab25f9ce() Unknown
> Qt6Core.dll!00007ffab6924105() Unknown
> Qt6Widgets.dll!00007ffaab517db3() Unknown
> QtWidgets.pyd!00007ffaab09f5c3() Unknown
> Qt6Widgets.dll!00007ffaab4d3b51() Unknown
> Qt6Widgets.dll!00007ffaab4d2c49() Unknown
> QtWidgets.pyd!00007ffaab29035f() Unknown
> Qt6Core.dll!00007ffab68d88c1() Unknown
> Qt6Core.dll!00007ffab68daf52() Unknown
> Qt6Gui.dll!00007ffab62c773f() Unknown
> Qt6Core.dll!00007ffab6a6f380() Unknown
> Qt6Gui.dll!00007ffab62c76b9() Unknown
> Qt6Core.dll!00007ffab68df4f4() Unknown
> Qt6Widgets.dll!00007ffaab70dd5c() Unknown
> Qt6Widgets.dll!00007ffaab743fb7() Unknown
> Qt6Widgets.dll!00007ffaab742401() Unknown
> QtWidgets.pyd!00007ffaab1b71f6() Unknown
> python313.dll!00007ffae0f7ea3c() Unknown
> python313.dll!00007ffae0f9b045() Unknown
> python313.dll!00007ffae0f9a9b5() Unknown
> python313.dll!00007ffae0f9d735() Unknown
> python313.dll!00007ffae0f9b727() Unknown
> python313.dll!00007ffae0f83a5f() Unknown
> python313.dll!00007ffae10c1597() Unknown
> python313.dll!00007ffae10c14c2() Unknown
> python313.dll!00007ffae0f9b045() Unknown
> python313.dll!00007ffae0f9a9b5() Unknown
> python313.dll!00007ffae0f9d735() Unknown
> python313.dll!00007ffae0f9b727() Unknown
> python313.dll!00007ffae0fc57b7() Unknown
> python313.dll!00007ffae0fe694e() Unknown
> QtCore.pyd!00007ffae0873a85() Unknown
> QtCore.pyd!00007ffae0873eca() Unknown
> QtCore.pyd!00007ffae0873f84() Unknown
> QtCore.pyd!00007ffae08763af() Unknown
> Qt6Core.dll!00007ffab68e5881() Unknown
> Qt6Core.dll!00007ffab69241e2() Unknown
> Qt6Widgets.dll!00007ffaab4d3b51() Unknown
> Qt6Widgets.dll!00007ffaab4d2c49() Unknown
> QtWidgets.pyd!00007ffaab29035f() Unknown
> Qt6Core.dll!00007ffab68d88c1() Unknown
> Qt6Core.dll!00007ffab68daf52() Unknown
> Qt6Gui.dll!00007ffab62c773f() Unknown
> Qt6Core.dll!00007ffab6a6f380() Unknown
> Qt6Gui.dll!00007ffab62c76b9() Unknown
> Qt6Core.dll!00007ffab68df4f4() Unknown
> Qt6Core.dll!00007ffab68d6f5a() Unknown
> QtWidgets.pyd!00007ffaab1963d5() Unknown
> python313.dll!00007ffae0f7ea6e() Unknown
> python313.dll!00007ffae0f9b045() Unknown
> python313.dll!00007ffae0f9a9b5() Unknown
> python313.dll!00007ffae0f9fa39() Unknown
> python313.dll!00007ffae0ff0c40() Unknown
> python313.dll!00007ffae0ff0ae6() Unknown
> python313.dll!00007ffae0ff0141() Unknown
> python313.dll!00007ffae0feffc4() Unknown
> python313.dll!00007ffae0fdf651() Unknown
> python313.dll!00007ffae1093044() Unknown
> python313.dll!00007ffae0f5cdd8() Unknown
> python313.dll!00007ffae0f5e699() Unknown
> python313.dll!00007ffae0f5e488() Unknown
> python313.dll!00007ffae0f5daef() Unknown
> pythonw.exe!00007ff6797b124a() Unknown
> kernel32.dll!00007ffb9e157374() Unknown
> ntdll.dll!00007ffba007cc91() Unknown
Other threads
Not Flagged 16504 0 Worker Thread ThreadPoolForegroundWorker Qt6WebEngineCore.dll!00007ffaaf2190f8
Not Flagged > 11616 0 Worker Thread CrBrowserMain ucrtbase.dll!00007ffb9d6df05b
Not Flagged 30976 0 Worker Thread msvcrt.dll thread libmmdevice_plugin.dll!00007ffab8e343d8
Not Flagged 24664 0 Worker Thread mswsock.dll thread mswsock.dll!00007ffb9ce110ab
Not Flagged 32536 0 Worker Thread ucrtbase.dll thread python313.dll!00007ffae1078457
Not Flagged 21716 0 Worker Thread ThreadPoolSingleThreadForegroundBlocking1 Qt6WebEngineCore.dll!00007ffaaf2190f8
Not Flagged 32532 0 Worker Thread winmm.dll thread winmm.dll!00007ffb8b172751
Not Flagged 32048 0 Worker Thread NetworkService Qt6WebEngineCore.dll!00007ffaaf213374
Not Flagged 24748 0 Worker Thread VizCompositorThread Qt6WebEngineCore.dll!00007ffaaf2190f8
Not Flagged 16008 0 Worker Thread VideoCaptureThread win32u.dll!00007ffb9e03a124
Not Flagged 25052 0 Worker Thread Chrome_ChildIOThread Qt6WebEngineCore.dll!00007ffaaf213374
Not Flagged 22932 0 Worker Thread Chrome_InProcGpuThread Qt6WebEngineCore.dll!00007ffaaf2190f8
Not Flagged 18280 0 Worker Thread ThreadPoolForegroundWorker Qt6WebEngineCore.dll!00007ffaaf2190f8
Not Flagged 30520 0 Worker Thread ThreadPoolForegroundWorker Qt6WebEngineCore.dll!00007ffaaf2190f8
Not Flagged 1976 0 Worker Thread ThreadPoolForegroundWorker Qt6WebEngineCore.dll!00007ffaaf2190f8
Not Flagged 32192 0 Worker Thread ThreadPoolForegroundWorker Qt6WebEngineCore.dll!00007ffaaf2190f8
Not Flagged 25424 0 Worker Thread CompositorTileWorker1 Qt6WebEngineCore.dll!00007ffaaf219221
Not Flagged 19232 0 Worker Thread ThreadPoolSingleThreadCOMSTASharedForeground0 win32u.dll!00007ffb9e03a124
Not Flagged 15916 0 Worker Thread ntdll.dll thread ntdll.dll!00007ffba00d0f84
Not Flagged 21776 0 Worker Thread ThreadPoolForegroundWorker Qt6WebEngineCore.dll!00007ffaaf2190f8
Not Flagged 3876 0 Worker Thread ntdll.dll thread ntdll.dll!00007ffba00d0f84
Not Flagged 11080 0 Worker Thread ucrtbase.dll thread mswsock.dll!00007ffb9ce18c5c
Not Flagged 13644 0 Worker Thread ucrtbase.dll thread python313.dll!00007ffae0fbaf02
Not Flagged 18808 0 Worker Thread ucrtbase.dll thread python313.dll!00007ffae0fbaf02
Not Flagged 11148 0 Worker Thread ucrtbase.dll thread python313.dll!00007ffae0fbaf02
Not Flagged 30652 0 Worker Thread ntdll.dll thread ntdll.dll!00007ffba00d0f84
Not Flagged 18136 0 Worker Thread BrokerEvent Qt6WebEngineCore.dll!00007ffab0a1b1d4
Not Flagged 32628 0 Worker Thread ThreadPoolServiceThread Qt6WebEngineCore.dll!00007ffaaf2190f8
Not Flagged 22216 0 Worker Thread ThreadPoolForegroundWorker Qt6WebEngineCore.dll!00007ffaaf2190f8
Not Flagged 23768 0 Worker Thread ThreadPoolBackgroundWorker Qt6WebEngineCore.dll!00007ffaaf2190f8
Not Flagged 6220 0 Worker Thread Chrome_IOThread Qt6WebEngineCore.dll!00007ffaaf213374
Not Flagged 19936 0 Worker Thread ucrtbase.dll thread python313.dll!00007ffae0fbaf02
Not Flagged 22076 0 Worker Thread ThreadPoolSingleThreadSharedBackgroundBlocking2 Qt6WebEngineCore.dll!00007ffaaf2190f8
Not Flagged 7332 0 Worker Thread ThreadPoolForegroundWorker Qt6WebEngineCore.dll!00007ffaaf2190f8
Not Flagged 31448 0 Worker Thread MemoryInfra Qt6WebEngineCore.dll!00007ffaaf2190f8
Not Flagged 29384 0 Worker Thread ThreadPoolBackgroundWorker Qt6WebEngineCore.dll!00007ffaaf2190f8
Not Flagged 7308 0 Worker Thread QThread win32u.dll!00007ffb9e035ce4
Not Flagged 31876 0 Worker Thread tokio-runtime-worker _rsbridge.pyd!00007ffab7ba2d00
Not Flagged 18556 0 Worker Thread ucrtbase.dll thread python313.dll!00007ffae1078457
Not Flagged 18160 0 Worker Thread ucrtbase.dll thread python313.dll!00007ffae0fbaf02
Not Flagged 29472 0 Worker Thread ucrtbase.dll thread python313.dll!00007ffae0fbaf02
Not Flagged 7580 0 Worker Thread msvcrt.dll thread libvlccore.dll!00007ffaaa77ec24
Not Flagged 21588 0 Worker Thread ucrtbase.dll thread python313.dll!00007ffae0fbaf02
Not Flagged 23060 0 Worker Thread ucrtbase.dll thread python313.dll!00007ffae0fbaf02
Not Flagged 31612 0 Worker Thread combase.dll thread combase.dll!00007ffb9f8bf646