# BUG: webinar.participant\_left webhook sometimes not fired

**URL:** <https://devforum.zoom.us/t/bug-webinar-participant-left-webhook-sometimes-not-fired/69552>\
**Category:** API and Webhooks\
**Tags:** webinar, webhooks\
**Created:** [May 25, 2022, 6:10pm UTC](https://devforum.zoom.us/t/bug-webinar-participant-left-webhook-sometimes-not-fired/69552 "2022-05-25T18:10:26Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Craig.H](https://sea2.discourse-cdn.com/flex016/user_avatar/devforum.zoom.us/craig.h/32/38005_2.png) [@Craig.H](https://devforum.zoom.us/u/Craig.H)\
**Post date:** [May 25, 2022, 6:10pm UTC](https://devforum.zoom.us/t/bug-webinar-participant-left-webhook-sometimes-not-fired/69552/1 "2022-05-25T18:10:26Z")

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## Using this template helps us debug your issues more effectively 🙂

**Description**  
I have developed a webhook-only based app for my local town (of which I’m currently Mayor) to allow webinar participants to see on the live app who is present as a “participant” in our virtual & hybrid town meetings. This is implemented using webhooks to deliver participant\_joined/participant\_left notifications which I track and then display in a simple UI.

This mostly works, except I have noticed that sometimes participant\_left notifications are not sent when a participant leaves. There’s no connection to my HTTP server to deliver them, and no record of them in the “Call Logs → Webhook Logs” on the App Marketplace management screens.

An example from yesterday: MeetingID 82646534251; Meeting UUID: V7cKDe0YSSeuIdgy51QzqA== participant.user\_id: 16882688 a webinar.participant\_joined webhook was correctly delivered at 2022-05-24T23:36:41.591Z; the user left the meeting (per admin Dashboard) at 2022-05-24T23:44Z but no webhook was ever sent for that. I wasn’t in the meeting, but I believe that the join/leave pair here might have been when the user was promoted to a panelist and then demoted back to attendee, based on what the main admin Dashboard shows

**Error**  
No error message - webhook just was never delivered for an event.

**Which App Type (OAuth / Chatbot / JWT / Webhook)?**  
Webhook

**Which Endpoint/s?**  
[https://pv-zooms.rungie.com/hook](https://pv-zooms.rungie.com/hook)

**How To Reproduce (If applicable)**  
Not sure - I only have 2 solid records of this happening. One is the case above with Meeting ID 82646534251 Meeting UUID V7cKDe0YSSeuIdgy51QzqA== and participant\_user\_id 16882688

The second was from the same meeting, with participant.user\_id 16872448 - joined event received at 2022-05-24T23:34:52.176Z but no leave event ever came through. Dashboard shows again that seems to have been a promotion to panelist and then a demotion back to attendee at 2022-05-24T23:38Z but no leave event was ever delivered

**Screenshots (If applicable)**  
N/A

**Additional context**  
This worked fine for many other promote/demotes - just occasionally seems to be not working.

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<div class="post-metadata">

**Author:** ![system](https://us1.discourse-cdn.com/flex016/uploads/zoomdeveloper/original/3X/6/1/614bdd549b610bbaa46ff934617683a02bdaa03c.png) [@system](https://devforum.zoom.us/u/system)\
**Post date:** [June 25, 2022, 4:10am UTC](https://devforum.zoom.us/t/bug-webinar-participant-left-webhook-sometimes-not-fired/69552/2 "2022-06-25T04:10:32Z")

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Closed on June 25, 2022, 4:10am UTC

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