Error ist replicable. Even if I reinstall Anaconda using the freshly downloaded Windows 64bit version from the Anaconda website, I get the same error again. Ananconda version 2025-06. Conda version is 25.5.1. Is there an alternative package available, that can be upgraded to 2.7.0 or an 2.7.0 version directly?
Hello,
As announced in my last post above, I executed an uninstall and fresh reinstall. This time I selected Miniconda because I know which packages are essential for me:
Installation of Miniconda with the current installer, I got conda 25.9.1.
Installation of anaconda-navigator via CLI.
Launch of Navigator in CLI, I got version 2.6.6.
Update Navigator to current version 2.7.0 via Navigator: It was successful! 
Installation of a customer environment via Navigator for my AI project.
Installation of all packages which I do need via Navigator into the customer environment.
I have a working installation! 
Best regards,
Same/similar issue here: Update Anaconda Navigator today and cannot launch it anymore. IMHO, such a situation is a nuclear meltdown for any software developer.
Calling up the Anaconda Prompt shows the following two error lines before the prompt appears:
Error while loading conda entry point: conda-libmamba-solver (module ‘libmambapy’ has no attribute ‘QueryFormat’)
Error while loading conda entry point: conda-libmamba-solver (module ‘libmambapy’ has no attribute ‘QueryFormat’)
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Thank you for the information. I now have again a working environment on 2.6.6 and I’ll probably stay with it until a solution with Anaconda Navigator is available. The work around via Miniconda may be something for more experienced users.
Hi,
Glad to hear that we’re finding some solutions for now! @grsc now you have a clean installation I would recommend not installing anything else into your base environment and keeping conda up to date.
I’ve been doing some more research and found a thread over on Stackoverflow from 1 year ago where the same issue has been found, and conda update conda has been working for some people.
The fact that the thread there started before Navigator 2.7.0 was released makes me think it must just be a new dependency of Navigator in this version that is causing the issue for people using older versions of conda. Unfortunately, no one there has been able to work out exactly which package it is causing the issues too… We will continue to investigate!
Thanks,
Jack
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Hello,
Here is a quick update on the steps (I still haven’t been able to update Anaconda Navigator to 2.7.0).
On a freshly installed machine with:
Edition: Windows 11 Pro
Version: 25H2
Installed on: 2025-11-25
OS build: 26200.7171
Experience: Windows Feature Experience Pack 1000.26100.265.0
1 – I downloaded Anaconda3-2025.06-0-Windows-x86_64.exe and installed it. This step completed successfully, and I can run Navigator (2.6.6).
2 – I executed the following commands:
conda install setuptools=78.1.1
conda install anaconda-client=1.13.1
conda update --all --dry-run --solver=classic (everything correct)
conda update --all --solver=classic
3 – After that, Anaconda Navigator stops working and shows this message:
(base) C:\Users\uuuu>anaconda-navigator
Traceback (most recent call last):
File “d:\anaconda3\Scripts\anaconda-navigator-script.py”, line 6, in
from anaconda_navigator.app.main import main
File “d:\anaconda3\Lib\site-packages\anaconda_navigator\app\main.py”, line 19, in
from anaconda_navigator.app.start import start_app
File “d:\anaconda3\Lib\site-packages\anaconda_navigator\app\start.py”, line 32, in
from anaconda_navigator.widgets.main_window import MainWindow
File “d:\anaconda3\Lib\site-packages\anaconda_navigator\widgets\main_window_init_.py”, line 48, in
from anaconda_navigator.widgets.dialogs.channels import DialogChannels
File “d:\anaconda3\Lib\site-packages\anaconda_navigator\widgets\dialogs\channels.py”, line 27, in
from conda_token import token_list
ModuleNotFoundError: No module named ‘conda_token’
4 – I performed a downgrade of conda-token as suggested:
conda install --name base conda-token=0.6.1
After this, Anaconda Navigator (still version 2.6.6 because conda update --all does not upgrade it) starts working again.
5 – Attempt to update Navigator through the GUI: failed
6 – Attempt to update Navigator through the terminal: failed
(base) C:\Users\uuuu>conda update anaconda-navigator --dry-run --solver=classic
3 channel Terms of Service accepted
Retrieving notices: done
Collecting package metadata (current_repodata.json): done
Solving environment: -
Found conflicts! Looking for incompatible packages.
Hello, I am also having this issue. I have tried a number of things, but so far nothing has worked. Does anyone have a fix for this issue?
Hello.
I had the same issue, but finally in manage to update to 2.7.0 on a Mac OS
conda install setuptools=78.1.1
conda install anaconda-client=1.13.1
conda update --all
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