Online experiment "Unknown Resource" issue

I also have the same issue - the experiment is able to load all .bmp files when I run it offline, but only three out of four images when I run it online, with the same error code as others are getting here. All images are in the same place (the main Pavlovia folder) and I also tried reuploading. I can’t see any difference between the images.

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Actually scratch that - the image file wasn’t in the html repository. I added and it works now. I don’t fully understand why all images didn’t upload to the same place though.

I am glad for you! However my problem is with uploading the Trials_List.csv file. I have tried to add it to the htlm forlder ( and i any other folder), and still not working.

Have you tried html/resources?

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BMP files aren’t ideal for online. PNG is probably the best lossless format

Good shout. Francesca, did you try the resources folder? If not, could you try deleting the experiment on Pavlovia and re-uploading? See e.g. Create new experiment from existing file

Hi all,
I managed to solve the problem by uploading resources trough the prompt. For some reason, the sync options doesn’t work properly with me. But more in general I have issues with pychopy when it has to refer to .csv or -xlsx condition files.

I have the same problame and I tried to change the names. Could you pls help me?

this is the massage I get:


the name of my experiment is HIS1

I can’t find your paradigm on pavlovia, but i think your resource files aren’t loaded correctly at the beginning. (I also had this problem)
Deactivate your project, empty your browser cache (just to be safe) and activate it again. If this isn’t the solution you can delete your whole project online and upload it again with a different name.

Can you also share a screenshot of the welcome screen, where the resources are loaded?

thank you for your fast replay.
it works now

cheers :slight_smile:

I am experiencing the exact same problem.
I have a bunch of png files that need to be displayed and I always get the error message

I tried everything. Adding the png extension to the path column in my excel file, getting rid of all spaces in the paths, all files are in both the html and the resources folder, because I don’t know where the heck they need to be, so better be safe than sorry. Is it the complete path that is only available on my computer? Somebody please help, I am working on my bachelor thesis and I am wasting so much time by not getting this done!

Thanks in advance <3

I’m experiencing the same problem.

It works fine localy, but not online.
I’ve tried everything, and it is driving me crazy.

link to the experiment: Sign in · GitLab

Many thanks!

Sorry you haven’t had a reply to this before. You seem to be trying to load the png files from your Desktop, which won’t work online. Check the path in your image components.


I’m not sure, but you seem to have the JS files uploaded in three locations (root, html and html/resources) so it’s possible that you are running the experiment from the wrong one. I had some difficulties with this and found that having broken something with an experiment I needed to run it from the root, not the html sub directory.

Also, do try a hard refresh with Ctrl-Shift-R

Thanks very much for answering my post, @wakecarter! I’ll try to keep the files in only one folder. I’ll update this topic when I finished to do that. Thanks again!

I seem to be experiencing the same thing. The funny thing is the exercise loop doesn’t seem to have any problems. The trial conditions files are assigned by a code snippet, which I have checked multiple times for any errors.
This is the experiment:

Dear David (and Wakefield mentioned in the following message),

Sorry for ‘pinging’ this old message… I’m kind of a newbie with Pavlovia… I have a problem that I think is related to the issue of not having a html folder in my project. I tried making a second project with the same experiment but still no html folder. My issue is that I use images called within code components in this experiment, and I think they are not loaded in the online experiment (I get ReferenceError). As @wakecarter mentioned in his crib sheet, this expectedly result in a failure to find the images. Manually moving the images to the ‘html/resources’ local folder should do the trick (I hope), but since I do not have this folder in the gitlab project ( or in my local folder on my computer, I do not know what to do. Out of desperation, I even tried to manually create a ‘html’ folder, but it did not result in a success.
The experiment is an IGT and works fine locally.

I’d be really thankful if you were to have any insight regarding my situation. Do not hesitate to ask if you need more information.


P.S.: Best wishes for the new year!

Okay, I found how to create the html folder. I just had to write ‘html’ as the output path in the ‘online’ tab of the general settings in the builder.

I still get a “ReferenceError: StimList not defined” error… maybe it has something to do with how I defined the list in my task. It works fine locally but not online, so maybe it has something to do with the JS code (I use shuffle() and create arrays of arrays because each list is made of different elements of different lists…). So I’ll go back to understand how JS works, because I suspect the error stem from my lack of skills in JS.
At least now, the images are loaded in the online experiment.


Hi Jean,

PsychoPy doesn’t create (or need) the html folder any more to reduce the duplication of resources on the Pavlovia server. Resources are selected by adding them in the online tab.

Best wishes