Online experiment stuck at 'Initialising the experiment' screen

Hi there,

I’ve been working on an experiment with four different versions, and I’m currently trying to upload and pilot the last two. I’ve used the same ‘skeleton’ in creating all versions but for some reason the last two are not loading online. All versions work perfectly offline and the first two load online with no issues.

I’ve not used the coder view at all, I have a very basic understanding of coding, it’s all been made using the builder.

I’m also not sure how to share the experiment with you, I can’t make it available on Pavlovia at this stage as it would need to be approved by the technicians at my university. Unless this works? Sign in · GitLab

I’ve taken a screenshot of the message I get on the web console. Does it give any hints as to what the issue might be?

Please help! :crying_cat_face:


On psychopy you can compile your your exp to javascript. This will open in the Coder view. Then check what is happening in line 238 as the error points to this line number.


Hi @Yiannis, this is line 238:

psychoJS.experiment.dataFileName = ((“.” + “/”) + (u’data/%s_%s_%s’ % [expInfo[‘参加者の ID: (名前の最初の文字)+(姓の最初の文字)+(電話番号の最後の4桁) 例: 名前 : 大阪花子 (Hanako Osaka),\u3000電話番号: 06-1331-1092 => ID: HO1092’], expName, expInfo[‘date’]]));

Trying to figure out what the unexpected string refers to here… any ideas?

This perhaps could be an issue with the Japanese characters (I assume they are Japanese). A more experienced PsychoPy user can perhaps answer this.

In the meantime, if I were you my approach on this would be to “reset” the exp info* - gear icon on Builder and then edit Experiment Info in the Basic tab and Data filename in the Data tab. Check to see if works. If it does then I would start adding this extra info you have already one at a time using English words first and if it works fine I would start changing these English words into Japanese.

*Create a new exp to see how the default exp info looks like.


Yes I would agree that this would be to do with the use of Japanese characters here - could you test without to be sure?

Hi @Yiannis @Becca , I didn’t factor in any issues with the Japanese characters as I had uploaded this experiment before (but using an older version of PsychoPy - 2021.1.2 to be precise) and it ran perfectly online.

I can’t help but think it might be an issue related to the newest version. I’m currently trying to download previous versions and upload it again but I’m having issues running them (they just won’t launch).

Hi There! I think it is because older versions of PsychoPy didn’t allow adaptable datafile names (it always used a default filename, ignoreing what was in the data > filename box)!!

Thanks @Becca , this makes sense. So is there a way to have a message in Japanese whilst on the loading screen prior to the experiment, that would prompt participants to create an ID? Using the latest version that is.

I think what you could do is have it so that the experiment settings field is still in Japanese (so participants are prompted) but they do not use that in the filename (it isn’t ideal I know but it would give you a means to get started! and the participant field should still be store in the data file itself!!)


Brilliant! Thanks @Becca , this seems to have solved my issue. For the purpose of our experiment we’re not too fussed with having participants’ IDs in the filename but it’s definitely worth looking into fixing this in future versions!! Some studies will just have to be typed in non-English characters. :sweat_smile:

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