TypeError error

[mg5171]

Hello,
I’m going back to an experiment I had run in August–which used to work just fine–and no longer works. The experiment involves preloading zip files of audio and image files. Here’s the demo link: https://farm.pcibex.net/r/LcCzmC/

This is the error:

Uncaught (in promise) TypeError: Cannot set properties of null (setting 'controls')
    at c.window.PennController._AddElementType.uponCreation (PennController.js:46)
    at c.n.uponCreation (PennController.js:39)
    at PennController.js:39
    at new Promise (<anonymous>)
    at Array.<anonymous> (PennController.js:39)
    at PennController.js:39

Any ideas on why this is happening? I’ve tried various browsers. I had an issue with the names of the Controller.name column in the results file, which I fixed, and I’m not sure if that’s related. And the website the files are loading from are labeled with http://www., which was a previous issue I had that threw an error.
Thanks!

[Jeremy]

Hello,

I am able to run your experiment, but it happened a few times that I refreshed it and the audios wouldn’t preload correctly, despite the zip file being successfully downloaded. In my experience, it happened less with Chrome than with Firefox

I am not sure what causes this problem, unfortunately. I’ll investigate it

Jeremy

[mg5171]

Hi Jeremy–thanks. The problem just got fixed by uploading the same files into a new experiment. I still don’t know what the error was, but the new version is working so you don’t have to worry about this!

[Jeremy]

Hi,

Glad to hear the new experiment runs better for you, but I actually doubt that the problem has been fixed. I think it has something to do with the timing of creation and preloading of resources, which is different whether your browser uses cached files or not. Creating a new experiment might have simply prevented your browser from using its cache, and it could be that taking the new experiment again later, you encounter the same problem. I’ll let you know if I identify the problem more precisely and, hopefully, fix it

Jeremy

[mg5171]

I found the actual error–one of my image files was ‘uploaded’ on my server with the correct name (so on some level PCIbex was able to ‘find’ it), but had a file size of 0 and was actually not there when I tried to access it. Since fixing that, everything works perfectly.

[Jeremy]

Great! Just in case the problem recurs, you should know that I’m actively working on the next version of PennController. It is still work in progress, but you can find my most recent build here. I improved the way zip files are downloaded and resources are preloaded

Jeremy

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