Participant encounters unspecified javascript error

URL of experiment:

Description of the problem: One of my participants told me that they encountered this error, but when I run it online myself it runs without problems. Same for the rest of my participants. Can it be that this person is opening it on the wrong browser (if there is such a thing as a wrong browser) or something similar? Or is there something that I should fix on my end?

Any help is highly appreciated :slight_smile:

Hi @Rebecca_Anagnost, thanks for flagging, please have you any information as to what browser, make and version, they are using? x

Google Chrome/Version 90.0.4430.72 (Official version) (64 bytes).
She also tried on Microsoft Edge, but the same error appears.

OK interesting, I see nothing out of the ordinary in the main script and like you was unable to reproduce on Chrome 90. But if running on Edge no good either, could the problem be machine specific? I have created a support fork based on PsychoPy latest in case that makes a difference, x

@sotiri thank you very much for your answer. I would also guess that the problem is machine-specific. The support fork you sent me works on my computer, can I try to share this with the participant? If I do, will the results be saved to my profile as would happen with the original link?

Thanks again for your help :slight_smile:

No problem @Rebecca_Anagnost, yes the data should still be available in csv format as part of the support fork repository and separate from the original. Please let me know how it goes, here to help :blush:

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Hi @sotiri,

I just wanted to chime in as I am having a similar problem. I have an experiment which has been running for quite a while and there is one participant who is unable to run it due to an Unspecified Javascript error.

They are using:
Browser: Chrome
Version: 90.0.4430.85
Operating System: Windows NT 10.0
Flash Version: -1
Java Support: undefined

Would it be any use to use @wakecarter’s solution from his crib sheet recommending to changed the index.html file manually if the study runs in some but not all browsers?

If the experiment works on some browsers but not others try editing the index.html file directly to replace

<script type="text/javascript" src=""></script>


<script type="text/javascript" src=""></script>

Hi @Julia_Landsiedel, thanks for flagging. That edit is known to take care of certain incompatibilities when it comes to lack of WebGL rendering and is included in the latest version of PsychoPy. I see no harm in making that change to your project. Please feel free to follow up if that fails to solve the problem, x

Hi @sotiri
After so long my participant answered that the support fork worked! Thank you very much! Now I would like some more help with two things: first, could you please guide me on how to find the results of the experiment? You mentioned that they should be in the support fork repository, but where do I find that?
And second, the participant has to answer to the second experiment now, and I guess that they will have the same problem (unspecified javascript error) if I send the original link, so may I ask you to send me the link for the support fork also for the second experiment? The original link is the following:
Thank you in advance for all your help!

Hi @Rebecca_Anagnost, alright, glad to hear the study went well. The data should be available in this folder. Could you give me developer rights to the second project you mention so I can create a support fork for that too? x

hm the link to the folder gives me a 404 error.
You must have developer rights now :slight_smile:

OK, I’m in, thanks! Sorry, yes, you should be too, I had to give you access rights to the support fork as well :blush:

Great, thanks! I can see the results now :slight_smile: Whenever you have time, can you also send me the support fork link to the second experiment? Thanks again :blush:

Hi @Rebecca_Anagnost, no worries, OK I have created a support fork for your second project and upgraded that to PsychoPy latest like with the previous one, let me know how it goes, x

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Thanks for all your help :slight_smile: I’ll let you know as soon as participants try it.