# Issues connecting to MCP **URL:** \ **Category:** Help & Support\ **Created:** [June 22, 2026, 3:25pm UTC](https://forum.ankimcp.ai/t/issues-connecting-to-mcp/20 "2026-06-22T15:25:21Z")\ **Posts on this page:** 14\ **Page:** 1
**Author:** ![zoomiepie](https://forum.ankimcp.ai/letter_avatar_proxy/v4/letter/z/9fc29f/32.png) [@zoomiepie](https://forum.ankimcp.ai/u/zoomiepie)\ **Post date:** [June 22, 2026, 3:25pm UTC](https://forum.ankimcp.ai/t/issues-connecting-to-mcp/20/1 "2026-06-22T15:25:21Z")
I have intermittent success connecting to the snki mcp via claude. sometimes it works and sometimes it does not. anyone else experiencing th8is? ---
**Author:** ![Anatoly](https://forum.ankimcp.ai/user_avatar/forum.ankimcp.ai/anatoly/32/15_2.png) [@Anatoly](https://forum.ankimcp.ai/u/Anatoly)\ **Post date:** [June 22, 2026, 5:16pm UTC](https://forum.ankimcp.ai/t/issues-connecting-to-mcp/20/2 "2026-06-22T17:16:00Z")
Hi @zoomiepie , how do you connect? Tunnel, local http server? Can you give a little more details? ---
**Author:** ![zoomiepie](https://forum.ankimcp.ai/letter_avatar_proxy/v4/letter/z/9fc29f/32.png) [@zoomiepie](https://forum.ankimcp.ai/u/zoomiepie)\ **Post date:** [June 22, 2026, 8:45pm UTC](https://forum.ankimcp.ai/t/issues-connecting-to-mcp/20/3 "2026-06-22T20:45:27Z")
Anki 25.09.4 (d52ca669) (ao) Python 3.13.5 Qt 6.9.1 PyQt 6.9.1 Platform: Windows-11-10.0.26200-SP0 When loading Anki MCP Server: Traceback (most recent call last): File “C:\Users\user\AppData\Local\AnkiProgramFiles.venv\Lib\site-packages\aqt\addons.py”, line 250, in loadAddons **import** (addon.dir\_name) ~~~~~~~~~~ ^^^^^^^^^^^^^^^^ File “C:\Users\user\AppData\Roaming\Anki2\addons21\124672614\__init_\_.py”, line 109, in raise ImportError(“AnkiMCP Server: pydantic\_core not available”) ImportError: AnkiMCP Server: pydantic\_core not available ---
**Author:** ![zoomiepie](https://forum.ankimcp.ai/letter_avatar_proxy/v4/letter/z/9fc29f/32.png) [@zoomiepie](https://forum.ankimcp.ai/u/zoomiepie)\ **Post date:** [June 22, 2026, 8:46pm UTC](https://forum.ankimcp.ai/t/issues-connecting-to-mcp/20/4 "2026-06-22T20:46:08Z")
sorry, am using local http server and sometimes it will connect and sometimes will not connect and cannot pinpoint why ---
**Author:** ![Anatoly](https://forum.ankimcp.ai/user_avatar/forum.ankimcp.ai/anatoly/32/15_2.png) [@Anatoly](https://forum.ankimcp.ai/u/Anatoly)\ **Post date:** [June 23, 2026, 2:15am UTC](https://forum.ankimcp.ai/t/issues-connecting-to-mcp/20/5 "2026-06-23T02:15:52Z")
Hi @zoomiepie — thanks for the report, and sorry for the hassle! 🙏 Quick explanation of what that error means: the add-on needs one component (pydantic\_core) that can’t ship inside the add-on file because it’s specific to your OS — so it’s downloaded from PyPI the first time the add-on loads, then cached. The pydantic\_core not available error means that download didn’t complete. The “sometimes it works” part fits: a download that gets interrupted (slow/blocked network, VPN/proxy, or antivirus stepping in) will fail, but a later attempt often succeeds. To pin down the exact cause, could you share three things? 1. The download error dialog. Just before the ImportError you pasted, there should have been a popup saying something like “Failed to download pydantic\_core: …” — the part after the colon names the real reason (timeout, SSL error, connection blocked, etc.). That line is the key clue. 2. Your installed add-ons. Tools → Add-ons — a screenshot or list is perfect. I want to check whether another add-on might be interfering with this component. 3. The AnkiMCP add-on version. In Tools → Add-ons, select AnkiMCP Server — the version shows at the bottom of the window. (Latest is 0.21.2; if you’re behind, Check for Updates is worth doing first.) In the meantime, a few things that usually get you unblocked: - Restart Anki and let it retry — it re-attempts the download on each launch, and once it succeeds the component is cached and the error stops. - If you’re on a corporate network, VPN, or proxy, try a normal home/direct connection for the first successful load. - If you run antivirus/Windows Defender, it can occasionally block or lock the freshly-downloaded file — allowing Anki through usually resolves it. Post back that “Failed to download…” line plus your add-ons list and we’ll get to the bottom of it. 👍 ---
**Author:** ![Anatoly](https://forum.ankimcp.ai/user_avatar/forum.ankimcp.ai/anatoly/32/15_2.png) [@Anatoly](https://forum.ankimcp.ai/u/Anatoly)\ **Post date:** [June 23, 2026, 6:24am UTC](https://forum.ankimcp.ai/t/issues-connecting-to-mcp/20/6 "2026-06-23T06:24:40Z")
One more thing worth checking, since you’re on Windows — this error is very often antivirus / Windows Defender briefly locking or quarantining that downloaded component, which would explain the on-and-off behavior: - Check Defender’s quarantine log: Windows Security → Virus & threat protection → Protection history — look for any entry mentioning \_pydantic\_core.pyd or the AnkiMCP add-on folder. (Same for a third-party antivirus, if you use one.) - Quick fix to try: add the add-on’s cache folder to your antivirus exclusions: %APPDATA%\Anki2\addons21\\_cache (paste %APPDATA%\Anki2\addons21 into the File Explorer address bar to locate the folder.) Then restart Anki — once the component loads cleanly it’s cached and reused, so the error should stop. If Protection History does show a quarantine entry, that confirms the cause and we’ll harden the add-on against it on our side. 🙏 ---
**Author:** ![zoomiepie](https://forum.ankimcp.ai/letter_avatar_proxy/v4/letter/z/9fc29f/32.png) [@zoomiepie](https://forum.ankimcp.ai/u/zoomiepie)\ **Post date:** [June 23, 2026, 2:37pm UTC](https://forum.ankimcp.ai/t/issues-connecting-to-mcp/20/7 "2026-06-23T14:37:22Z")
Anki 25.09.4 (d52ca669) (ao) Python 3.13.5 Qt 6.9.1 PyQt 6.9.1 Platform: Windows-11-10.0.26200-SP0 Exception in thread Exception in threading.excepthook:Exception ignored in thread started by \\>Exception ignored in sys.unraisablehook===Add-ons (active)=== (add-on provided name [Add-on folder, installed at, version, is config changed]) Anki MCP Server [‘124672614’, 2026-06-20T11:53, ‘None’, ‘’] AnkiHub [‘1322529746’, 2026-06-03T09:43, ‘None’, ‘’] ===IDs of active AnkiWeb add-ons=== 124672614 1322529746 ===Add-ons (inactive)=== (add-on provided name [Add-on folder, installed at, version, is config changed]) **Here’s the claude destkop MCP logs:** 2026-06-23T14:31:37.613Z [anki] [info] Server started and connected successfully { metadata: undefined } 2026-06-23T14:31:38.828Z [anki] [info] Message from client: {“method”:“initialize”,“params”:{“protocolVersion”:“2025-11-25”,“capabilities”:{“extensions”:{“io.modelcontextprotocol/ui”:{“mimeTypes”:[“text/html;profile=mcp-app”]}}},“clientInfo”:{“name”:“claude-ai”,“version”:“0.1.0”}},“jsonrpc”:“2.0”,“id”:0} { metadata: undefined } 2026-06-23T14:32:38.842Z [anki] [info] Message from client: {“jsonrpc”:“2.0”,“method”:“notifications/cancelled”,“params”:{“requestId”:0,“reason”:“McpError: MCP error -32001: Request timed out”}} { metadata: undefined } 2026-06-23T14:32:38.843Z [anki] [info] Client transport closed { metadata: undefined } 2026-06-23T14:32:38.844Z [anki] [info] Server transport closed (renderer released port) { metadata: undefined } Add ons: ![image](https://uploads.ankimcp.ai/original/1X/b0f541168303c0ea379b56e797e262729d7caa44.png) Also, just checked for updates and appears to be updated. ---
**Author:** ![Anatoly](https://forum.ankimcp.ai/user_avatar/forum.ankimcp.ai/anatoly/32/15_2.png) [@Anatoly](https://forum.ankimcp.ai/u/Anatoly)\ **Post date:** [June 23, 2026, 7:52pm UTC](https://forum.ankimcp.ai/t/issues-connecting-to-mcp/20/8 "2026-06-23T19:52:30Z")
Thanks @zoomiepie — this is really helpful, especially the add-on list and the Claude Desktop logs. Here’s where we are: those logs tell us the add-on’s background server thread is crashing while handling the connection (that’s why Claude Desktop’s request hangs and then times out after 60 seconds). But the actual error message behind that crash isn’t being captured anywhere you can easily share — it only goes to a place GUI users never see — so we can’t yet pinpoint the exact cause from what’s available. We have a couple of strong theories (a possible clash with another add-on’s bundled libraries, or the platform-specific component not loading cleanly), but we don’t want to guess. So here’s the plan: we’re shipping a new version with proper debugging built in — an optional “log to file” setting that records the full error plus a snapshot of your environment, in a file you can attach here. That will show us exactly what’s failing on your machine instead of us guessing. I’ll update this thread as soon as that version is out, with simple steps: update → flip on the logging option → keep using Anki normally → and when it next misbehaves, send us the log file. That should let us nail it down quickly. 🙏 In the meantime, if you want to experiment: temporarily disabling AnkiHub and restarting is a quick way to tell whether the two add-ons are conflicting — if AnkiMCP works with AnkiHub off, that’s a strong clue for us. Thanks for your patience while we get you a proper diagnostic build! ---
**Author:** ![Anatoly](https://forum.ankimcp.ai/user_avatar/forum.ankimcp.ai/anatoly/32/15_2.png) [@Anatoly](https://forum.ankimcp.ai/u/Anatoly)\ **Post date:** [June 25, 2026, 6:29pm UTC](https://forum.ankimcp.ai/t/issues-connecting-to-mcp/20/9 "2026-06-25T18:29:32Z")
Hi @zoomiepie — good news: I’ve just shipped v0.22.0 with built-in diagnostic logging that captures the real reason behind the pydantic\_core not available error (instead of the cryptic message you saw). That should let me pin down exactly what’s happening on your machine. Could you do the following? 1. Update both Anki and the add-on first - Update Anki to the latest version (it’s worth doing regardless — a newer Anki may resolve this on its own). - Update the add-on: Tools → Add-ons → select AnkiMCP Server → Check for Updates (you want v0.22.0). 1. Turn on logging - Tools → Add-ons → select AnkiMCP Server → Config, set: “log\_to\_file”: true - Save, then restart Anki. (This works even if the add-on currently fails to load.) 1. Reproduce, then send the log - Use Anki as you normally would until the error happens again (since it’s intermittent, it may take a restart or two). - Then open Tools → AnkiMCP Server Settings… and click Open log folder (in the Diagnostics section) — attach ankimcp.log from there. While you’re in that dialog, clicking Copy diagnostics and pasting the result here helps too. - If the add-on failed to load and the menu item isn’t there: get the log via Tools → Add-ons → select AnkiMCP Server → View Files → user\_files → ankimcp.log instead. A couple of notes: - The log captures the failure even when the add-on fails to load, so don’t worry if the server isn’t starting. - Secrets (API keys, tokens) are automatically redacted, so it’s safe to post the file publicly. Once I see the log, I hope I will understand what’s going on. ---
**Author:** ![Anton\_Hejmmeyer](https://forum.ankimcp.ai/letter_avatar_proxy/v4/letter/a/3e96dc/32.png) [@Anton\_Hejmmeyer](https://forum.ankimcp.ai/u/Anton_Hejmmeyer)\ **Post date:** [June 29, 2026, 3:51pm UTC](https://forum.ankimcp.ai/t/issues-connecting-to-mcp/20/10 "2026-06-29T15:51:27Z")
Hi, I’ve got no experience at all with computers and am kind of desperate. This was my debug info… Anki 26.05 (e64c6b1a) (ao) Python 3.13.11 Qt 6.11.0 PyQt 6.11.0 Platform: macOS-15.7.3-arm64-arm-64bit-Mach-O When loading Anki MCP Server: Traceback (most recent call last): File “/Users/runner/work/anki/anki/out/installer/build/anki/macos/app/Anki.app/Contents/Resources/app\_packages/aqt/addons.py”, line 247, in loadAddons File “/Users/anton/Library/Application Support/Anki2/addons21/124672614/ **init**.py”, line 211, in raise ImportError(“AnkiMCP Server: pydantic\_core not available”) ImportError: AnkiMCP Server: pydantic\_core not available And this was the information it gave me: Failed to download pydantic\_core: No module named ‘distutils’ Please check your internet connection and try again. My conection is 200mbps so I’m clueless. ---
**Author:** ![Anatoly](https://forum.ankimcp.ai/user_avatar/forum.ankimcp.ai/anatoly/32/15_2.png) [@Anatoly](https://forum.ankimcp.ai/u/Anatoly)\ **Post date:** [June 29, 2026, 5:51pm UTC](https://forum.ankimcp.ai/t/issues-connecting-to-mcp/20/11 "2026-06-29T17:51:36Z")
Hi @Anton_Hejmmeyer! Thanks for the details, and don’t worry — this isn’t your internet, and it’s not something you did wrong. The error usually means another add-on you have installed is clashing with AnkiMCP. Honestly, this kind of clash is hard for us to reproduce and fix — it only happens with a certain mix of add-ons, so on our own computers everything works fine. That’s why your help really matters here. Two quick things would help a lot: 1. Show me which add-ons you have. - In Anki, open Tools → Add-ons. - Click any add-on in the list, then click View Files (bottom right). - A folder opens. Click up one level so you’re in the folder called addons21. - Send me a screenshot of what’s inside — it’ll be a set of numbered folders. Those numbers tell me exactly which add-ons you have. 1. A quick, safe test (optional but very helpful). - Back in Tools → Add-ons, click every add-on except Anki MCP Server, and press Toggle Enabled to turn it off. - Restart Anki. - If AnkiMCP now loads fine, one of those add-ons is the cause — and we can turn them back on one at a time to find which. (Turning them off is completely safe and fully reversible.) Thanks so much for your patience — once I see those folder numbers, I should be able to tell you what’s going on. ![image](https://uploads.ankimcp.ai/original/1X/c3f4f026256ebf61de8e5d9fe9e72f7c2e4feb73.png) ---
**Author:** ![Anton\_Hejmmeyer](https://forum.ankimcp.ai/letter_avatar_proxy/v4/letter/a/3e96dc/32.png) [@Anton\_Hejmmeyer](https://forum.ankimcp.ai/u/Anton_Hejmmeyer)\ **Post date:** [June 30, 2026, 12:14am UTC](https://forum.ankimcp.ai/t/issues-connecting-to-mcp/20/12 "2026-06-30T00:14:34Z")
![Bildschirmfoto 2026-06-30 um 02.10.04](https://uploads.ankimcp.ai/original/1X/1dd30aaa032cdacadc8d2f217608507818e7a6a9.jpeg) ![Bildschirmfoto 2026-06-30 um 02.11.09](https://uploads.ankimcp.ai/original/1X/3549a76c7bb23a5386e81f14324188a7fee56c71.jpeg) ![Bildschirmfoto 2026-06-30 um 02.10.31](https://uploads.ankimcp.ai/original/1X/92c2ab4a832ffa74eb74a43c2d77f80321c26cd3.jpeg) Hi, thanks for the quick reply. I’ve tried my best, hope this is what you need… ---
**Author:** ![Anatoly](https://forum.ankimcp.ai/user_avatar/forum.ankimcp.ai/anatoly/32/15_2.png) [@Anatoly](https://forum.ankimcp.ai/u/Anatoly)\ **Post date:** [June 30, 2026, 1:47am UTC](https://forum.ankimcp.ai/t/issues-connecting-to-mcp/20/13 "2026-06-30T01:47:33Z")
I understand that you have only 3 addons, right? Can you show content of last folder too, **addons21**? I mean folder with the numbers, it’s ids of the addons installed. I will try to install them and reproduce the issue. ---
**Author:** ![Anatoly](https://forum.ankimcp.ai/user_avatar/forum.ankimcp.ai/anatoly/32/15_2.png) [@Anatoly](https://forum.ankimcp.ai/u/Anatoly)\ **Post date:** [June 30, 2026, 6:04am UTC](https://forum.ankimcp.ai/t/issues-connecting-to-mcp/20/14 "2026-06-30T06:04:10Z")
Good news — I tracked it down, and it’s fixed. The crash is caused by a clash with the AMBOSS add-on. AMBOSS includes its own older copy of a small helper library, and on the current Anki that old copy is broken. Because AMBOSS loads before AnkiMCP, AnkiMCP was being forced to use that broken copy — which is what produced the “No module named ‘distutils’” message. So it was never your internet or anything you did wrong. I’ve fixed this on our side: AnkiMCP now always uses its own correct copy of that library, so other add-ons can’t interfere anymore. I’ll be releasing an update later today. Once the update is out: 1. In Anki, open Tools → Add-ons, select Anki MCP Server, and click Check for Updates. 2. Restart Anki. After that it’ll work normally, even with AMBOSS installed — nothing else for you to do.