Task fails to continue. A white screen appears instead.

Deni

Hi,

I'm having an issue with a sequence of tasks created on Jatos. A few weeks ago, my colleague created a sequence of tasks on Jatos (e.g., a digit span task and a go no-go task both written in jsPsych). The two versions of jsPsych are different though because the digit span task was written with an older version. However, until a couple of days ago, everything was running fine. Participants were able to access to the experiment online (from their smartphone with different browsers : Chrome, Safari) and complete both tasks.

However, we have been experiencing a problem now. When we try to run the experiment, I am able to start the first task (digit span), but it doesn't allow me to complete it. After a certain time the full screen becomes white and the results of the task are not recorded. Additionally, I am not able to continue with the second task in line (in this case the go no-go task).

What could the problem be? Is it possible that the old version of the jsPsych might be the issue? If so, why only now (and not 2 weeks ago)?

Eventually, does this mean that I have to re-write the whole task with a new version of jsPsych or is there any alternative solution?

Thank you,

Deni

elisa

Hi Deni,

If it worked before, it might work again. What changed in between, did you update anything? Which server are you using?

Also, it's good that you can reproduce the error. It makes troubleshooting possible. Can you open the console (under Developer tools in your browser) and see if you get any errors?

Elisa

Deni

Thanks Elisa for your prompt reply.

We did not update anything. We are having issues using Google Chrome Android.

The error is attached here:

Thanks

Deni

Just to clarify, the problem doesn't seem to be during the task per se. It seems to be between one task and the next one, the results are not recorded and participants cannot proceed to the following task.

Many thanks.

kri

Hi Deni!

In the screenshot I can see that jatos.js cannot send the result data. It tries 5x and then gives up. That is strange since there are no other errors in the console (or are there?).

I have a couple of questions:

Can you please check in the Network tab of your Dev Tools what the HTTP return code of all the failed requests is?

Do you have an admin account on your JATOS? If yes, can you please have a look at the logs there (Admin -> logs), especially around the time when one of those failed result data sending is happening and look for errors or exceptions there?

Another thing that comes to my mind (although this would be weird), since this JATOS endpoint is the only one during study running that is using a HTTP PUT, is it possible that something somehow doesn't allow PUT requests to go through?

Best,

Kristian

Deni

Hi Kristian,

Thanks for your reply.

The error is 403.

Please see the attached file to answer your second question.

Many thanks

Line.txt

kri

From you log I can see that you try to load the same component again although this is not allowed in your study properties:

13:24:16,094 [INFO] - publix_access - GET /publix/e04515dd-d645-4288-a766-ba0262123665/8f0ed4b4-104d-4960-babb-d35b608b1539/start

This causes the study run to get finished:

13:24:16,117 [INFO] - publix_access - GET /publix/e04515dd-d645-4288-a766-ba0262123665/end?successful=false&message=It%27s+not+allowed+to+reload+this+component+%28ID%3A+229%29.+Study+%28ID%3A+195%29+is+finished.

And subsequent sending of result data doesn't work anymore, because finished study runs do not accept new result data:

I can see those errors in your log "PublixException during call /publix/e04515dd-d645-4288-a766-ba0262123665/8f0ed4b4-104d-4960-babb-d35b608b1539/resultData: Study run is already finished (study result 1336)".

I assume there were other failed requests in the network tab of your browser's dev tools indicating the fail to reload the component.

Your course of action should be to figure out what is causing the reloading of the component in your study's code. There are jatos.js functions to control the study flow, e.g. to start another component jatos.startComponent, jatos.startComponentByPos, jatos.startComponentByTitle, jatos.startNextComponent, and jatos.startLastComponent. A good starting point is to find all occurrences of these functions.

I hope this helps.

Best,

Kristian