Unable to upload editable material on an INDICO Event

Dear community,

I wanted to raise an exception we found when trying to upload editable material into one Indico Event we created at our facility, in November.

Some of the stakeholders - editors of material - were not able to upload their contents into the server.

“Something went wrong” (bad request 400).

This error has not been able to be reproduced. As a workaround, a person with administration-permissions could upload the material of the contributors that could not upload their content by themselves.

Some of the editors that found same error were administrators, as well.

Could you please, look at it, share what could have prevented users to upload the content?
(we know it was not related with the size of the files: as same files could be uploaded by other administrators, at same day others could not do it)…

Thanks in advance,

Beatriz L. (ALBA Synchrotron Light Source)

Hi, it would be useful to see the actual error response from the server. Without this there’s nothing we can do…

The easiest way to see it would be opening the browser’s developer tools in order to see the response. Unfortunately this would need to be done BEFORE submitting the form to upload material (and then “hope” that it fails).

Who could we reach if it happens again? Do you have any previous case / experience of a case similar than this in the past?
If yes, what did you learn/find out then?

(Ref. 35th Meeting of ALBA Scientific Advisory Committee (15-16 November 2022) · ALBA (Indico) (cells.es))

Without more details there’s not much that can be done even if it happens again unless it’s reproducible… If you figure out the error that’s returned from the server, please post it in here!

PS: You should update to the latest version! Not related to this issue though, we did not change anything related to uploading materials.

We upgraded the solution into the “last” version in April. Kindly advise if there is any newer upgrade, though.

Thanks, Adrian!



Yes there is. There should be a notice about an upgrade being available in the admin area.

OK, thanks for the response.

We will try to reproduce “in real-time” the actual error response from the server if this error happens again. Keep you posted.


As it is a error 400, I would guess it actually came from the webserver, not the indico uwsgi application behind. Are the relevant error logs from the webserver still available? They may have more informations.

Also relevant could be the used browsers as these may be relevant here.

400 can also happen when a required GET/POST argument is missing (flask automatically converts the KeyError from accessing request.form['foo'] etc. to a 400 error)