# \*\*Unspecified JavaScript error\*\*

**URL:** <https://discourse.psychopy.org/t/unspecified-javascript-error/15691>\
**Category:** Online experiments\
**Created:** [August 13, 2020, 8:54am UTC](https://discourse.psychopy.org/t/unspecified-javascript-error/15691 "2020-08-13T08:54:54Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![Duarte\_MM\_Pereira](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.psychopy.org/duarte_mm_pereira/32/9099_2.png) [@Duarte\_MM\_Pereira](https://discourse.psychopy.org/u/Duarte_MM_Pereira)\
**Post date:** [August 13, 2020, 8:54am UTC](https://discourse.psychopy.org/t/unspecified-javascript-error/15691/1 "2020-08-13T08:54:54Z")

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URL of experiment: [Pavlovia](https://pavlovia.org/Wzl.onscience/cscreen)

Description of the problem:  
When running my experiment on google chrome I get the following error:  
**Unspecified JavaScript error**  
the developer console shows the following:

 ![image](https://us1.discourse-cdn.com/flex002/uploads/psychopy/original/3X/a/b/ab6499ddb2cc783e6ddda4e0efb91136820affb9.png)

Google is not throwing up anything.

bw,

D.

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**Author:** ![thomas\_pronk](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.psychopy.org/thomas_pronk/32/9531_2.png) [@thomas\_pronk](https://discourse.psychopy.org/u/thomas_pronk)\
**Post date:** [August 14, 2020, 2:31pm UTC](https://discourse.psychopy.org/t/unspecified-javascript-error/15691/2 "2020-08-14T14:31:22Z")

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Tricky! If you get uninformative error messages, it can be useful to remove parts of your experiment until it does work; that gives you an idea of what part causes the error.

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**Author:** ![deblecourt](https://avatars.discourse-cdn.com/v4/letter/d/ec9cab/32.png) [@deblecourt](https://discourse.psychopy.org/u/deblecourt)\
**Post date:** [August 14, 2020, 3:43pm UTC](https://discourse.psychopy.org/t/unspecified-javascript-error/15691/3 "2020-08-14T15:43:23Z")

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I had the [same error](https://discourse.psychopy.org/t/unspecified-javascript-error-possibly-something-with-getting-framerate/15641). It was probably incompatibility between v2020.1 and v2020.2. Did you create the experiment in 2020.1, or put it online in 2020.1? Pavovia indicates this at ‘Platform Version’.  
Try Edit Experiment Settings -\> Use PsychoPy Version -\> 2020.1

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<div class="post-metadata">

**Author:** ![Duarte\_MM\_Pereira](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.psychopy.org/duarte_mm_pereira/32/9099_2.png) [@Duarte\_MM\_Pereira](https://discourse.psychopy.org/u/Duarte_MM_Pereira)\
**Post date:** [August 17, 2020, 8:59am UTC](https://discourse.psychopy.org/t/unspecified-javascript-error/15691/4 "2020-08-17T08:59:29Z")

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Thank you! this worked. In the newest psychopy standalone version, I went to experiment settings and selected what version of psychopy it should to run on.

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<div class="post-metadata">

**Author:** ![Duarte\_MM\_Pereira](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.psychopy.org/duarte_mm_pereira/32/9099_2.png) [@Duarte\_MM\_Pereira](https://discourse.psychopy.org/u/Duarte_MM_Pereira)\
**Post date:** [August 18, 2020, 10:22am UTC](https://discourse.psychopy.org/t/unspecified-javascript-error/15691/5 "2020-08-18T10:22:10Z")

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So I got the same error again after having to fix a problem with a conditional loop exit. This time after creating this portion of the experiment from scratch on the newest version of standalone.

what I have tried:  
removing all code components and just running the experiment in its simplest forms  
forcing to run various different versions of psychopy (inc. 2020.1 and 2020.2)

The pavlovia link:

> **[Pavlovia](https://pavlovia.org/Wzl.onscience/pilotscr)**
>
> The place for the wide community of researchers in the behavioural sciences to run, share, and explore experiments online