500 Internal Server error for Intermediate Webhook Catch Event

[csh3]

Hi everyone,

I’m getting a 500 internal server error when I send a webhook to an intermediate catch event. I’m using Postman, and sending to a running process instance that I also kicked off from Postman with a webhook start event (without issue). Can anyone figure out why this is happening or give tips on how to debug?

The webhook is configured to the POST method, without auth at the moment.

This is my payload:

{"opportunity_id":"123","won_lost":"Won"}

I’m using Camunda Cloud and thus don’t have access to more detailed logging associated with Camunda self-hosted.

Thanks for your help,

[nathan.loding]

Hi @csh3 - just to get the easy questions out of the way:

1. you started a process that has an existing variable opportunity_id with the value of “123”?
2. that process is using the most recent deployed model?
3. and that process is still active and hasn’t ended?

[csh3]

Hi Nathan!

1. Yes, the correlation key and values match exactly
2. Yes
3. Yes

Thanks!

[nathan.loding]

Hi @csh3 - what version of Camunda is your cluster on? Have you updated it to 8.4 yet? 8.4 comes with some new features, including having some further visibility into webhook events within the Webhook tab in Web Modeler.

[csh3]

Hi Nathan,

Thanks for the tip. We upgraded our cluster to Zeebe 8.4. I’m seeing that the requests are coming in from the web modeler, but I’m still getting a 500 “internal server error” from Postman.

Here’s a screenshot for you reference:

Thanks for taking a look, I really appreciate the time.

[csh3]

Ok, for future reference I got this to work finally. I just deleted the intermediate webhook event and remade it. I’m guessing the webhook got corrupted or something weird on the backend.

[sbuettner]

Hey,
we checked your result expression and it looks like it missed the curly braces:

request.body.won_lost

If its a scalar value you would need to map it like this:

{"won_lost": request.body.won_lost}

[nathan.loding]

Hi @sbuettner - is that something csh3 should be able to see in the Webhook tab logs? Do you have any suggestions for troubleshooting/debugging this in the future?

[sbuettner]

Yes, we will add respective logs to the Webhook tab in the Web-Modeler with 8.5alpha1.

[csh3]

Hi!
Thanks for your reply. Looking forward to the enhanced transparency / validation logic here. Thanks for your help in the mean time.