VSCode Hangs when Connecting to kernel: Python 3.12.1: Activating Python Environment 'Python 3.12.1'

[Keeks77]

Environment data

• VS Code version: 1.102.2
• Jupyter Extension version (available under the Extensions sidebar): 2025.6.0
• Python Extension version (available under the Extensions sidebar): 2025.10.1
• OS (Windows | Mac | Linux distro) and version: Wondows
• Python and/or Anaconda version: 3.12.1
• Type of virtual environment used (N/A | venv | virtualenv | conda | ...): NA
• Jupyter server running: Local | Remote | Local

Expected behaviour

jupyter notebooks would run

Actual behaviour

Jupyter notebook does not connect to the python Environment See attached screenshot - it just seems to hang at this step. Happens after latest update

Other version

Name: ipykernel
Version: 6.28.0

I am not sure if this is a general issue or just with my setup so please let me know if you need any more info

[Keeks77]

Tried to Uninstall and Install again both Juypter and Python extensions but did not help

From Jupyter.log

Visual Studio Code (1.102.2, undefined, desktop)
Jupyter Extension Version: 2025.6.0.
Python Extension Version: 2025.10.1.
Python Environment Extension Version: 1.2.0.
Pylance Extension Version: 2025.7.1.
Platform: win32 (x64).
Home = c:\Users\xxxx.xxxxx
Temp Storage folder ~\AppData\Roaming\Code\User\globalStorage\ms-toolsai.jupyter\version-2025.6.0
Workspace folder c:\Data\Jupyter
08:52:19.901 [info] Starting Kernel (Python Path: ~\AppData\Local\Programs\Python\Python312\python.exe, Unknown, 3.12.1) for 'c:\Data\Jupyter\Checks\Any.ipynb' (disableUI=true)
08:52:20.329 [error] Failed to refresh the list of interpreters

[DonJayamanne]

Please can you check the logs in the Python extension
Use the command Python: Show Output to get to the Python extension logs. there might be some errors there.

[Keeks77]

@DonJayamanne here you go

2025-07-29 08:52:18.687 [info] Native locator: Refresh started
2025-07-29 08:52:18.715 [info] > pyenv which python
2025-07-29 08:52:18.715 [info] cwd: .
2025-07-29 08:52:18.740 [info] > conda info --json
2025-07-29 08:52:20.329 [info] Native locator: Refresh finished in 1824 ms
2025-07-29 08:52:20.537 [info] Active interpreter [c:\Data\Jupyter]: c:\Users\xxx.xxxx\AppData\Local\Programs\Python\Python312\python.exe
2025-07-29 08:52:21.395 [info] > ~.conda\Scripts\conda.exe info --json
2025-07-29 08:52:21.396 [info] > ~.condarc\Scripts\conda.exe info --json
2025-07-29 08:52:22.263 [info] Starting Pylance language server.

[Keeks77]

when i disable Pylance extension I can now run my notebooks....i will do some more checking but it will probably be tomorrow

[DonJayamanne]

when i disable Pylance extension I can now run my notebooks

THank you for getting back
Looks like an issue in pylance extension or the like.
Please could you file an issue on their repo.

08:52:20.329 [error] Failed to refresh the list of interpreters

This too indicates there's something wrong with the Python extension (possible the Pylance was causing issues with Python extension or the like)

Closing for now, if you feel its been closed prematurely or the issue is in fact in the jupyter extension, please do let me know and I'll re-open this.

[Keeks77]

@DonJayamanne Maybe I was wrong...it didn't completely fix my issue. I also had to stop Python Enironments externsion to get my notebooks to work.

log output below.

First it would stop ant the Starting Pylance language server and freeze there. When you stop the Pylance extension ti would move on and stop at starting Starting Jedi language server for Jupyter and then freeze then

When you stop the Python Environments extension the notebooks then work..... I will see if i can investigate is more but will raise an issue on the Pylance repo first since it freezes there first

2025-07-29 10:07:42.600 [info] Native locator: Refresh started
2025-07-29 10:07:42.600 [info] > pyenv which python
2025-07-29 10:07:42.600 [info] cwd: .
2025-07-29 10:07:42.621 [info] > conda info --json
2025-07-29 10:07:44.067 [info] Active interpreter [c:\Data\Jupyter]: c:\Users\xxx.xxxx\AppData\Local\Programs\Python\Python312\python.exe
2025-07-29 10:07:44.152 [info] Native locator: Refresh finished in 1648 ms
2025-07-29 10:07:45.292 [info] > ~.conda\Scripts\conda.exe info --json
2025-07-29 10:07:45.294 [info] > ~.condarc\Scripts\conda.exe info --json
2025-07-29 10:07:45.882 [info] Starting Pylance language server.
2025-07-29 10:08:06.186 [info] > conda info --json
2025-07-29 10:08:06.186 [info] > pyenv which python
2025-07-29 10:08:06.186 [info] cwd: .
2025-07-29 10:08:06.942 [info] Active interpreter [c:\Data\Jupyter]: c:\Users\xxxx.xxxx\AppData\Local\Programs\Python\Python312\python.exe
2025-07-29 10:08:08.035 [info] > ~.conda\Scripts\conda.exe info --json
2025-07-29 10:08:08.036 [info] > ~.condarc\Scripts\conda.exe info --json
2025-07-29 10:08:08.181 [info] Starting Jedi language server for Jupyter.
2025-07-29 10:09:48.303 [info] Native locator: Refresh started
2025-07-29 10:09:48.303 [info] > conda info --json
2025-07-29 10:09:48.313 [info] > pyenv which python
2025-07-29 10:09:48.313 [info] cwd: .
2025-07-29 10:09:48.367 [info] Conda environment manager found at: C:\Program Files\Microsoft SQL Server\150\PYTHON_SERVER\Scripts\conda.exe
2025-07-29 10:09:48.367 [info] Using conda: C:\Program Files\Microsoft SQL Server\150\PYTHON_SERVER\Scripts\conda.exe
2025-07-29 10:09:48.550 [info] Native locator: Refresh finished in 786 ms
2025-07-29 10:09:48.555 [info] Python interpreter path: ~\AppData\Local\Programs\Python\Python312\python.exe
2025-07-29 10:09:49.946 [info] Starting Jedi language server for Jupyter.
2025-07-29 10:09:50.485 [info] > ~.conda\Scripts\conda.exe info --json
2025-07-29 10:09:50.488 [info] > ~.condarc\Scripts\conda.exe info --json
2025-07-29 10:09:54.757 [info] Native locator: Refresh started
2025-07-29 10:09:54.797 [info] Conda environment manager found at: C:\Program Files\Microsoft SQL Server\150\PYTHON_SERVER\Scripts\conda.exe
2025-07-29 10:09:54.797 [info] Conda set to: C:\Program Files\Microsoft SQL Server\150\PYTHON_SERVER\Scripts\conda.exe
2025-07-29 10:09:55.107 [info] Native locator: Refresh finished in 350 ms

[DonJayamanne]

. I also had to stop Python Enironments externsion to get my notebooks to work.

Re-opening and transferring to python Extension repo