Unable to edit event with 400 error

Dear Indico Team,

We had the similar issue as this post ☞ Unable to upload editable material on an INDICO Event
(We can add attachments or create events.)

“Something went wrong”(Bad request 400) message is occur when remove attachment, open ‘Workflows’, etc.

Probably the DELETE and PUT methods don’t seem to work…

The DELETE method worked until March 13th. We haven’t changed any settings since then, but suddenly the problem occurs.
We did a version update (3.2.0 → 3.2.3) today hoping that the error will be resolved, but it’s still in progress.

We have uploaded captured image below that might be helpful in resolving the issue.

There are no error logs in /log/indico.log and /log/apache/error.log…

Please let me know if there is any additional information needed to resolve this issue.

Thank you in advance.
Woo-Been, Institute for Basic Science

You mostly have a poorly configured WAF (web app firewall) in front of Indico which breaks those requests. Check the actual response body in your browser’s dev tools; maybe that helps you figure out what’s causing it.