Opensesame installation failed on Windows 11
I tried to install Opensesame 4.1 and it fails, it just repeats two same code lines:
INFO:pyt_code_editor.worker.manager:stop_unused workers called: max_free=1, found 1 free workers
INFO: pyat_code_editor.worker manager: No free workers to stop.
I tried to pause windows security and to run opensesame as administrator but the outcome is the same. Also ChatGPT recommended installing older version but I can't find it either. What should I do?
Comments
Hello @chavudin
Are you trying to install Opensesame with the Standard Windows installer? (here) If you could be more specific (i.e., add details, when does it fail, how/at what step, what did you do, etc.) and paste the full error/traceback, we may be able to help.
Thanks,
Claire
Check out SigmundAI.eu for our OpenSesame AI assistant! 🤖
Hello, @cvanbuck
Yes, I tried with standard windows installer and everything goes normal until it starts checking for free workers. There is no error warning it just continues searching for free workers, here you can see what’s showed in cmd:
INFO:pyqt_code_editor.mixins.symbols:Initializing symbols
INFO: pyt_code_editor.mixins.check: Initializing Check
INFO:pyqt_code_editor.syntax_highlighters.syntax_highlighter:failed to load syntax nigh sped
INFO: pyqt_code_editor.mixins. file link: Initializing FileLink
INFO:pyqt_code_editor.mixins.complete:Initializing Complete
INFO: pyat_code_editor.mixins.complete:Complete initialized.
INFO:pyqt_code_editor.mixins.base:modified: True
INFO: pyat_code_editor.mixins.base:modified: False
INFO:pyat_code_editor. worker.manager: stop_unused workers called: max_free=1, found 0 free workers
INFO: pyt_code_editor.worker.manager:No free workers to stop.
INFO: pyt_code_editor.mixins.check:Requesting lint check
INFO:pyqt_code_editor.worker.manager:Creating new worker 392 for request check
INFO:pyqt_code_editor._settings:Found 54 settings in total
INFO: pyt_code_editor.mixins.base:Sent request to worker 392, now tracking 1 active requests.
INFO: pyat_code_editor.worker manager:Creating new worker 13244 for request matching_brackets
INFO: pyt_code_editor._settings :Found 54 settings in total
INFO:pyat_code_editor.mixins.base:Sent request to worker 13244, now tracking 2 active requests.
INFO:pyqt_code_editor.worker.manager:Marking worker 392 as free
INFO:pyqt_code_editor.mixins.base:Received worker result from 392: action=check
INFO:pyqt_code_editor.worker.manager:Marking worker 13244 as free
INFO:pyqt_code_editor.mixins.base:Received worker result from 13244: action=matching_brackets
INFO: pyt_code_editor.mixins.highlight_matching_brackets:Handling matching brackets result
INFO: pyt_code_editor. worker.manager: stop_unused_workers called: max_free=1, found 2 free workers
INFO:pyqt_code_editor.worker.manager:Stopping free worker 13244 because we have too many.
INFO:pyqt_code_editor.worker.manager:Finished stopping unused workers.
INFO:pyqt_code_editor.worker.manager: stop_unused workers called: max_free=1, found 1 free workers
INFO:pyqt_code_editor.worker manager:No free workers to stop.
INFO:pqt_code_editor.worker.manager: stop_unused workers called: max_free-1, found 1 free workers
INFO:pyqt_code_editor.worker.manager:No free workers to stop.
INFO:pyat_code_editor.worker.manager: stop_unused_workers called: max_free=1, found 1 free workers
INFO:pyqt_code_editor.worker.manager: No free workers to stop.
INFO:pyqt_code_editor.worker.manager:stop_unused workers called: max_free=1, found 1 free workers
INFO:pyqt_code_editor.worker.manager:No free workers to stop.
INFO:pyat_code_editor.worker.manager: stop_unused workers called: max_free=1, found 1 free workers
INFO: pyt_code_editor.worker. manager: No free workers to stop.
INFO: pygt_code_editor.worker.manager:stopunused_workers called: max_free-1, found 1 free workers
INFO: pyt_code_editor.worker.manager:No free workers to stop.
INFO:pyat_code_editor.worker.manager: stop_unused workers called: max_free=1, found 1 free workers
INFO:pyqt_code_editor.worker.manager:No free workers to stop.
INFO:pyt_code_editor.worker.manager:stop_unused workers called: max_free=1, found 1 free workers
INFO: pyat_code_editor.worker manager: No free workers to stop.
I tried few times and same thing happens, first time I’ve let it go for more than 20 mins and than stopped it.
Also I tried with Opensesame 3.3 megapack installer and installation process freezes when checking for OSF settings, i tried to do it with and without internet connection and the outcome is the same, it just stopps and disk usage is 0%.
Thank you for support!
PS.
Should I try to install it with conda?
Hi @chavudin
Hmm, I'm not sure what the issue is here. Does it only happen when you try to install Opensesame, or does it also happen with other software?
Yes, try installing it with Conda in case it's an environment, permissions or network issue (e.g., if your device managed by an institution) that Conda can bypass.
Let us know how it goes,
Claire
Check out SigmundAI.eu for our OpenSesame AI assistant! 🤖
Hi @cvanbuck
It happened only with Opensesame. Those should not be the issue but I tried Conda, and even after I install additional packages it says I need, Opensesame reports this: ImportError: Qt bindings are not installed (I made sure PyQt is installed). So far I've tried to install 4.1 and 3.3. My professor recommended to try 4.0 because it works better on his computer, so I'll try that.
Nevertheless, thank you for your help! If you have any other advice I'll try that.
Hi @cvanbuck
Sorry to bother you again. I'm writing just to update about my problem. I tried again to install 4.1 and 4.0 versions, in both cases installation doesn't finish, this time it stopped on checking for updates (that's what is the last line in cmd). I ended that task and tried to use Opensesame, it allows me to design experiments but doesn't allow me to run them. Also on the second try to open it it crashed totally.
Again, thank you for support!
Hi @chavudin
OK, unfortunately, I have no idea what's happening. I'll ask Sigmund, our Opensesame AI expert, and paste its response below to see if it helps.
Claire
Check out SigmundAI.eu for our OpenSesame AI assistant! 🤖
Sigmund: Those “stop_unused workers…” lines are not the installer and not the real error. They come from OpenSesame’s embedded code editor (pyqt_code_editor) doing background linting. When you see the console stuck repeating them, what’s usually happening is: OpenSesame is hung somewhere else (often Qt / graphics backend init / update check / permissions), and the only thing still printing is the editor worker manager.
Given your later updates (“stopped on checking for updates”, can open GUI but can’t run experiments, then crashes), this fits a broken/partial install + failing runtime dependencies scenario.
The most important clue is the conda error you got:
>
ImportError: Qt bindings are not installedThat almost always means: you installed
opensesamebut didn’t get a working Qt runtime in that env (or you startedopensesamefrom a different Python than the env you installed into).What I’d do (in this order)
pyqt(Qt bindings) and uses conda-forge.conda activate ..., runwhere pythonandwhere opensesameto confirm paths point into that env.conda update.I put the exact commands + a small “sanity check” in the workspace so you can verify Qt imports before launching OpenSesame.
---
## Windows 11: pinpoint why OpenSesame hangs / won’t run
### A) Confirm you’re launching the conda-installed OpenSesame (not another one)
Open **Miniconda Prompt** and run:
```bash
conda activate os41
where python
where opensesame
python -c "import sys; print(sys.executable)"
```
All paths should contain:
`...\miniconda3\envs\os41\...`
If `where opensesame` points somewhere else (e.g., Program Files), you’re mixing installs.
---
### B) Confirm Qt bindings really work in that env
```bash
python -c "from PyQt6 import QtCore; print('PyQt OK', QtCore.QT_VERSION_STR)"
```
If this fails, paste the full error.
---
### C) Launch OpenSesame from the same prompt (so we capture the real error)
```bash
opensesame --debug
```
If it hangs at “checking for updates”, wait ~30s, then press Ctrl+C and paste the last ~30 lines shown.
---
### D) If OpenSesame opens but running an experiment crashes
In OpenSesame:
- **View → Show console**
- Run any minimal experiment
- Copy/paste the **first ERROR traceback** (ignore INFO lines)
Also try switching backend:
- Experiment → Properties (General properties) → **Backend**
- Try **legacy** (safest) and run again.
---
### E) Quick Win11 security check (common)
Windows Security → Virus & threat protection → Ransomware protection → **Controlled folder access**
- If ON: add an “Allow an app” exception for:
- `...\miniconda3\envs\os41\python.exe`
- `...\miniconda3\envs\os41\Scripts\opensesame.exe`
---
### What I need from you
Reply with:
1) Output of section **A**
2) Output of section **B**
3) What happens in **C** (and the last lines)
4) If you get an ERROR in **D**, paste it
I am Sigmund, your OpenSesame AI assistant! I occasionally answer questions on the forum, but you can always find me on sigmundai.eu!