# Stuck at initializing

**URL:** <https://discourse.psychopy.org/t/stuck-at-initializing/45511>\
**Category:** Builder\
**Tags:** online, pavlovia\
**Created:** [September 2, 2025, 2:30pm UTC](https://discourse.psychopy.org/t/stuck-at-initializing/45511 "2025-09-02T14:30:51Z")\
**Posts on this page:** 1\
**Showing post:** 2

<div class="post-metadata">

**Author:** ![JensBoelte](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.psychopy.org/jensboelte/32/9060_2.png) [@JensBoelte](https://discourse.psychopy.org/u/JensBoelte)\
**Post date:** [September 3, 2025, 7:44am UTC](https://discourse.psychopy.org/t/stuck-at-initializing/45511/2 "2025-09-03T07:44:19Z")

</div>

Hello @hyoji-ha

Did you successfully sync your experiment with the Pavlovia server? If the Platform version is unknown, then your JavaScript version of your experiment did not compile without errors despite running offline.

![grafik](https://us1.discourse-cdn.com/flex002/uploads/psychopy/original/3X/8/b/8b1de2c45888e5d129cd5dd848872c5fbea1cc35.png)

see here

> [@Wakefield's Daily Tips](https://discourse.psychopy.org/t/wakefields-daily-tips/43371/51):
>
> “initialising…” isn’t an error message If you try to run an experiment online and you get a blank screen with the word initialising… in the centre, you need to investigate further before asking for help. This indicates a [launch error](https://psychopy.org/online/psychoJSCodingDebugging.html#launch-errors-stuck-on-initialising-the-experiment), which is usually a syntax error in your JavaScript file that wasn’t caught by the checks during synchronisation, and may be in a Before Experiment code component tab. The most common cause for this error is that you are trying to import a Python library,…

You need to find the relevant code line to determine the problem. The above pasted code looks fine.

BTW. I am not sure if it is possible to change the slider labels online.

Best wishes Jens

---

_[View the full topic](https://discourse.psychopy.org/t/stuck-at-initializing/45511)._