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RUNNING online experiments output error message of Unable to save data for a PILOT session

URL of experiment: 1)
3) another similar experiment with different URL (seems I’m limited with 2 links max for now)

Description of the problem: RUNNING online experiments output error message of Unable to save data for a PILOT session. All three experiments were running and collecting data as expected from the data collection beginning day (March 27th) until March 29th (before server migration). However, the experiments could not be run at around 11:30PM March 29th(Korea Standard Time) with the error message of ‘404 NOT FOUND’. I suspect that was due to the server migration.
As of now (March 30th 11:00AM) the experiments successfully initialize but the data saving is not working with the following error window. I’ve released all the ‘reserved’ licenses just in case. I’ve also re-synced all three experiments (no changes made) from PsychoPy builder v2020.1.2 which all returned ‘successful sync’ message.

It seems pilot data cannot be saved if the status is “RUNNING”. Change the status to “PILOTING” would work.


Hello Heidi, thanks for the suggestion. However, the experiments are currently in RUNNING mode not PILOTING mode in experiment pages. Participants with URLs can also successfully open and initialize the experiments which would not be possible if the experiments are in PILOTING mode. But when the participants finish the session, error message above pops up. Does this mean that selecting ‘RUNNING’ is not reflected in the server copy? (accessible by participants but somehow still recognized as PILOTING mode?)

Again, everything was working just fine before server migration and nothing has changed in the experiment part including Pavlovia settings in experiments page. Now I’m getting dozens of mails from participants regarding the error message above…

Please help :frowning:

Hi Simon, I just tested on my experiment, the same happened. It can work well in PILOTING, but not RUNNING…

I canceled the assigned credits to avoid participants from doing it.

I see, so it means this problem is universal not specific to mine only. I guess we’ll have to wait until Jon or administrators see to this issue. In the mean time I should go cancel the assigned credits for now. thanks for confirming Heidi.

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Good morning @Simon_Kim and @ylchan,

The issue cropped up when we moved to the new server at the week-end. I have just fixed it.
My apologies for the mishap!
Best wishes,



Great! I just confirmed that all my experiments are working perfectly :slight_smile:

Thank you @apitiot

I am very glad!
Happy experimenting and do not hesitate to hit the forum, should you need assistance.


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