500 Server Error when creating study - ibt-hsg.herokuapp.com/api/sessions failing

[nataliakononov-spec]

Hi
I'm trying to create a new study but keep getting a 500 Internal Server Error when I click "Create Session":

Error ID: invalid_url_error
Error Message: Request to "https://ibt-hsg.herokuapp.com/api/sessions/" failed: 500 Server Error: Internal Server Error for url: https://ibt-hsg.herokuapp.com/api/sessions
Timestamp: 2025-11-21T17:46:00.276Z

Is there currently a server issue? Any estimated time for resolution?
Thanks for your help!

[Howquez]

Hi Natalia,

the server works just fine (it works if try to create a session with the placeholder csv https://raw.githubusercontent.com/DICE-app/sample-feeds/refs/heads/main/feeds/9gag.csv). I therefore assume that there is an issue with the csv file you created. Can you share the corresponding URL with me?

[nataliakononov-spec]

Hi,

Thanks for the quick response! Here's my CSV file URL:
https://drive.google.com/uc?export=download&id=1353yIuoe2N1GfHg0OlhWQdoAor92pEuQ

BTW The preview works fine - I can see all the posts displaying correctly.
Thanks,
Natalia

[Howquez]

When reading files from your gDrive, the software currently expects a slightly different pattern. I will test this and work on a solution or provide a more detailed answer.

But until then I would recommend you to just upload your csv file to github and then copy the raw URl. Can you verify whether this works?

[Howquez]

The Problem:
You tried to upload a CSV file from Google Drive to create a study session. The software rejected the link and threw an error ("invalid_url_error").

The Cause:
Google Drive links can have different formats. The software expected links in one specific format (like drive.google.com/file/d/FILE_ID/view) but you provided a link in a different format (like drive.google.com/uc?export=download&id=FILE_ID). The software tried to extract the file ID from the wrong part of the URL, which caused it to fail.

The Fix:
I updated the code to recognize both types of Google Drive link formats. Now the software can handle links that are already in the direct download format without trying to reconstruct them.

The Result:
You can now share your Google Drive files using either link format, and the software will process them correctly.

Thank you for reporting this issue! It helped me identify a gap in how the software handles different Google Drive URL formats, which will make it more robust for everyone ... hopefully 🤞.

[nataliakononov-spec]

Thank you so much, it works perfectly now.

[nataliakononov-spec]

Hi again,
The study was created successfully and I can access the consent page, but after clicking "Start" I get "Application error (500)" with the OTREE_PRODUCTION error message.
Session-wide link: https://ibt-hsg.herokuapp.com/join/tunupize
The CSV tests and previews fine in the DICE interface, but the actual session won't load.
Thanks again!
Natalia

[Howquez]

Just to confirm: you still use these stimuli?

https://drive.google.com/uc?export=download&id=1353yIuoe2N1GfHg0OlhWQdoAor92pEuQ

I just tested them and was able to create a session without issues. Unfortunately, we have not yet implemented web analytics, so I cannot see your specific configuration or settings. This makes it harder to diagnose the problem remotely.

One additional note: the frontend verification is not perfect. It mimics some of the backend logic but runs independently from it. This means that sometimes configurations pass the frontend checks but still fail when processed by the backend.

If I understand correctly, you successfully created a session 40 minutes ago, but now the same process no longer works. Did you change anything between then and now?

[nataliakononov-spec]

Hi,
Yes, I'm still using that CSV file: https://drive.google.com/uc?export=download&id=1353yIuoe2N1GfHg0OlhWQdoAor92pEuQ
Didn't make any changes to the file.
I successfully created the session about an hour ago (session ID: saoqckx3), but when I try to access it via the session-wide link (https://ibt-hsg.herokuapp.com/join/jatopoga)), it shows the welcome/consent page and the "Study Instructions", but after clicking "Next"

i get:
Application error (500)
Traceback
For security reasons, the error is not displayed here. You can view it with one of the below techniques:
Delete the OTREE_PRODUCTION environment variable and reload this page
Look at your Sentry messages (see the docs on how to enable Sentry)
Look at the server logs

[Howquez]

Yes, I saw that session but I cannot see how you configured it in the web app.

When I use that csv file without further adjusting any of the default settings, (see attached json) I can create this session and see the feed. In that feed, I can see that you configured the csv in a way that the first post is shwon on top while all the others are displayed as comments to this post.

Can you check whether you can access my session by clicking the link above? Can you also test what happens when you upload the json file (pretending to be a returning user)? Does it recreate the session?
341hszbo_dice_config.json

I am sorry for the inconvenience.

[Howquez]

Alternatively, can you reach out to hauke.roggenkamp@unisg.ch so that we schedule a quick zoom call?

[nataliakononov-spec]

Hi,
Yes! Your session works .
I also tested uploading your JSON file and creating a session from it, that works too.
Comparing the two configurations, I see that I used the "WIP: Generic" feed option. When I change it to "Twitter" it works.
Thank you so much for your help!
Natalia

[Howquez]

BTW: when testing the app and playing around with session configurations, please keep the sessions small to avoid unnecessary database strain. Hence, choose something like 10 study slots or so.