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Strange error loading file


I have the following error appear: " * unable to download resource: Boy in the snow.jpg (FILE_LOAD_ERROR)"

It is really bizzare, because sometimes the experiment runs smoothly and sometimes I get this error. The file is downloaded on Github and everything seems fine, but for some reason I am getting this error.

Hey! Maybe this tutorial could help you out? Thomas Pronk / tutorial_js_network_error · GitLab

Hi, thanks! Does it mean that the “unknown resource” error described in your tutorial is the same as the “unable to download resource” error?
Because I am getting the former one:

I also wonder if my error can occur because too many files are uploaded in this experiment? 80 images and 65 sounds…

I think that it is more likely to be an issue with your file names if you have brackets and full stops in them.

Thanks, I updated my filenames, but still get this error for some reason. I think it is different from the one which appears when you made an error in filename:

Moreover, sometimes when I reload the page - the error disappears and the experiment goes well. Sometimes it appears again.

Please could you show an example of an error? Where are the sound files in relation to the js file?

Could you convert them to mp3?

I found this searching for howler

Here is an example of an error:

The sound files are in the main folder directory, just like the js file.

Thanks, I’ll convert them to mp3 and see what happens.

Are you downloading files on the fly or are they all downloading before the experiment starts?

They are downloading before the experiment starts

Have you checked the capitalisation of the file name?

There are a bunch of possible solutions on the forum – follow this link for a few.

Have you tried reducing each file size or clearing the browser cashe prior to starting?

Thanks, yes, I tried all that.
It’s just surprising that sometimes that error appears (always the same), and sometimes the experiment is loaded without errors.

I just deleted the file which caused the error and uploaded a new one. Although I couldn’t figure out what was the problem with the initial file (I checked the capitalisation). Now it works fine and I didn’t have to reduce the file size.


Happy you’re back on track! I’d still recommend to recode your WAV files into MP3, because they are better supported by web-browsers. See: Media formats suitable for online studies — PsychoPy v2021.1

Yes, thank you, I already did! That is a good idea indeed.

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