# Experiment stuck on initialising - Pavlovia Pilot

**URL:** <https://discourse.psychopy.org/t/experiment-stuck-on-initialising-pavlovia-pilot/12219>\
**Category:** Online experiments\
**Created:** [April 8, 2020, 5:19pm UTC](https://discourse.psychopy.org/t/experiment-stuck-on-initialising-pavlovia-pilot/12219 "2020-04-08T17:19:07Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![Mengyuan\_L](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.psychopy.org/mengyuan_l/32/5866_2.png) [@Mengyuan\_L](https://discourse.psychopy.org/u/Mengyuan_L)\
**Post date:** [April 8, 2020, 5:19pm UTC](https://discourse.psychopy.org/t/experiment-stuck-on-initialising-pavlovia-pilot/12219/1 "2020-04-08T17:19:07Z")

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URL of experiment: [https://gitlab.pavlovia.org/juneliu/subliminal-reward-pre-test/blob/master/html](https://gitlab.pavlovia.org/juneliu/subliminal-reward-pre-test/blob/master/html)

Hi all,

My experiment is stuck on “initializing the experiment” but it runs well offline. I have uploaded my .js and legacy-brewers.js file (and to make sure, I created a NoModule.js file and copies codes of legacy-brewers.js to that file). I think there are problems with my js codes. Are there ways to check what exact problems in those codes?

Thank you so much!

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**Author:** ![esl342](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.psychopy.org/esl342/32/34648_2.png) [@esl342](https://discourse.psychopy.org/u/esl342)\
**Post date:** [January 7, 2025, 10:33pm UTC](https://discourse.psychopy.org/t/experiment-stuck-on-initialising-pavlovia-pilot/12219/2 "2025-01-07T22:33:17Z")

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Was there ever a solution to this? I’m having the same issue and can’t figure it out.

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**Author:** ![wakecarter](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.psychopy.org/wakecarter/32/5753_2.png) [@wakecarter](https://discourse.psychopy.org/u/wakecarter)\
**Post date:** [January 7, 2025, 10:41pm UTC](https://discourse.psychopy.org/t/experiment-stuck-on-initialising-pavlovia-pilot/12219/3 "2025-01-07T22:41:09Z")

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There are many many solutions to this – but the starting point is to identify the error.

I could take some guesses (are you importing any Python libraries) but ideally please could you look for the error in the developer tools.

> [@Wakefield's Daily Tips](https://discourse.psychopy.org/t/wakefields-daily-tips/43371/5):
>
> Developer Tools If you encounter an error in an online study, open the Developer tools console using Ctl-Shift-I in Windows/Chrome, Cmd-Opt-J or Cmd-Opt-I in Mac/Chrome, F12 in IE/Edge, Ctrl-Shift-J in Windows/Safari or Ctrl-Opt-J in Mac/Safari. Select the Console tab at the top and errors item on the left to view errors. Ignore the 404 error related to favicon.ico Look for the error that appears on the main screen and click on the link next to Scheduler.\_currentTask. Take…

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**Author:** ![esl342](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.psychopy.org/esl342/32/34648_2.png) [@esl342](https://discourse.psychopy.org/u/esl342)\
**Post date:** [January 8, 2025, 12:11am UTC](https://discourse.psychopy.org/t/experiment-stuck-on-initialising-pavlovia-pilot/12219/4 "2025-01-08T00:11:12Z")

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Thanks for your suggestion, Carter. I am not importing any Python libraries. I have had an almost identical experiment piloting just fine right now (it was pushed to Pavlovia in 2024).

Upon opening the Developer Tools, I have identified a few errors, though they don’t appear to be particularly informative:

```auto
task2_0B_X.js:1 
Failed to load resource: the server responded with a status of 404 ()

```

and then multiple attempts of the following:

```auto
debug.js:92
(3)(+0000114): Error: HTTP request to http://127.0.0.1:23119/connector/ping rejected with status 0

```

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<div class="post-metadata">

**Author:** ![wakecarter](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.psychopy.org/wakecarter/32/5753_2.png) [@wakecarter](https://discourse.psychopy.org/u/wakecarter)\
**Post date:** [January 8, 2025, 10:11am UTC](https://discourse.psychopy.org/t/experiment-stuck-on-initialising-pavlovia-pilot/12219/5 "2025-01-08T10:11:46Z")

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> [@esl342](#):
>
> ```auto
> task2_0B_X.js:1 
> Failed to load resource: the server responded with a status of 404 ()
> 
> ```

This error message is very informative. Go to Experiment Settings and change the experiment name to task2\_0B\_X. Then save and re-sync.

> [@Stuck on Initializing Screen](https://discourse.psychopy.org/t/stuck-on-initializing-screen/38423):
>
> URL of experiment: [Sign in · GitLab](https://gitlab.pavlovia.org/ep110/iowa_gambling_4choice_hcombined) Description of the problem: Though the experiment runs fine offline on PsychoPy, it gets stuck on an ‘initializing’ screen when running online on Pavlovia. Based on my research, it seems like it is probably an error in the JS code, but the developer tools have been unhelpful in finding the actually error. The error I get is: Failed to load resource: the server responded with a status of 404 (). There are no loaded in Python packages that seem to be a common i…

I’m not sure about the second error message – are you using a local browser test rather than on Pavlovia.