# C# SDK: Remove\_CB\_onUserLeft not triggering at random **URL:** \ **Category:** Windows\ **Created:** [October 28, 2021, 2:05pm UTC](https://devforum.zoom.us/t/c-sdk-remove-cb-onuserleft-not-triggering-at-random/59518 "2021-10-28T14:05:20Z")\ **Posts on this page:** 11\ **Page:** 1
**Author:** ![bragma](https://sea2.discourse-cdn.com/flex016/user_avatar/devforum.zoom.us/bragma/32/4213_2.png) [@bragma](https://devforum.zoom.us/u/bragma)\ **Post date:** [October 28, 2021, 2:05pm UTC](https://devforum.zoom.us/t/c-sdk-remove-cb-onuserleft-not-triggering-at-random/59518/1 "2021-10-28T14:05:20Z")
**Description** Hi, I’ve updated my C# App with wrapper v5.7.6.1079 and started to have problems with the user leave callback not being called. This happens at random. When this happens, if I ask the SDK the list of participants I see that the ID of the participant that left is still included, and will never timeout/leave. This is a major problem since I am using custom UI and tiles are never removed because I have no way to know that it happened. **Which Desktop Meeting SDK version?** C# wrapper v5.7.6.1079 ---
**Author:** ![Michael\_Condon](https://sea2.discourse-cdn.com/flex016/user_avatar/devforum.zoom.us/michael_condon/32/13543_2.png) [@Michael\_Condon](https://devforum.zoom.us/u/Michael_Condon)\ **Post date:** [October 28, 2021, 8:56pm UTC](https://devforum.zoom.us/t/c-sdk-remove-cb-onuserleft-not-triggering-at-random/59518/2 "2021-10-28T20:56:57Z")
Hey @bragma, Thanks for using the dev forum! It is nice to see you again 🙂 The C# wrapper is not actively maintained by Zoom and developer support is limited for it. However, if a bug exists in both the wrapper and the standard SDK, it is likely a bug with the SDK itself and we can investigate/resolve it. Can you run the C++ demo application and let me know if you see the same issue there? onUserLeave is already implemented there for both default and custom UI. If you do not see the same issue there, it is likely that the C# wrapper is not wrapping something properly and would have to be modified locally. Thanks! Michael ---
**Author:** ![bragma](https://sea2.discourse-cdn.com/flex016/user_avatar/devforum.zoom.us/bragma/32/4213_2.png) [@bragma](https://devforum.zoom.us/u/bragma)\ **Post date:** [October 29, 2021, 7:01am UTC](https://devforum.zoom.us/t/c-sdk-remove-cb-onuserleft-not-triggering-at-random/59518/3 "2021-10-29T07:01:21Z")
I’ll try but it may prove to be a hard task. The problem does not show up by just calling Remove\_CB\_onUserLeft and logging in the callback. I’ve found out that video must be on, and connection/disconnection must be repeated several times. Since I just swapped the SDK without touching my code (which worked for the past year) I was looking for some insight on what SDK internal changes may have caused the problem. ---
**Author:** ![bragma](https://sea2.discourse-cdn.com/flex016/user_avatar/devforum.zoom.us/bragma/32/4213_2.png) [@bragma](https://devforum.zoom.us/u/bragma)\ **Post date:** [October 29, 2021, 8:08am UTC](https://devforum.zoom.us/t/c-sdk-remove-cb-onuserleft-not-triggering-at-random/59518/4 "2021-10-29T08:08:24Z")
On a side note, do you have any idea on how it can happen that non only I don’t received the event, but also the user is still in the list of participants obtained from participantsController.GetParticipantsList() ? ---
**Author:** ![Michael\_Condon](https://sea2.discourse-cdn.com/flex016/user_avatar/devforum.zoom.us/michael_condon/32/13543_2.png) [@Michael\_Condon](https://devforum.zoom.us/u/Michael_Condon)\ **Post date:** [October 29, 2021, 8:03pm UTC](https://devforum.zoom.us/t/c-sdk-remove-cb-onuserleft-not-triggering-at-random/59518/5 "2021-10-29T20:03:17Z")
Hey @bragma, When are you calling participantsController.GetParticipantsList()? Thanks! Michael ---
**Author:** ![bragma](https://sea2.discourse-cdn.com/flex016/user_avatar/devforum.zoom.us/bragma/32/4213_2.png) [@bragma](https://devforum.zoom.us/u/bragma)\ **Post date:** [November 2, 2021, 9:57am UTC](https://devforum.zoom.us/t/c-sdk-remove-cb-onuserleft-not-triggering-at-random/59518/6 "2021-11-02T09:57:47Z")
@Michael_Condon A added a debug button to our client that causes a call to participantsController.GetParticipantsList(). Then I connect with our mobile app, and disconnect. After a few times (enter/leave), the Leave event is not called and the video in the tile of that user remains freezed. I press the debug button and log the list of users. The Id of that user is still in the list. ---
**Author:** ![bragma](https://sea2.discourse-cdn.com/flex016/user_avatar/devforum.zoom.us/bragma/32/4213_2.png) [@bragma](https://devforum.zoom.us/u/bragma)\ **Post date:** [November 2, 2021, 10:26am UTC](https://devforum.zoom.us/t/c-sdk-remove-cb-onuserleft-not-triggering-at-random/59518/7 "2021-11-02T10:26:19Z")
As a side note, we moved from v5.4.54802.0124 to v5.7.6.1079. but v5.7 showed the problem. In its state we can’t release. We tried v5.5.12511.0422 and it works, so the problems seems to be limited to v5.7 ---
**Author:** ![Michael\_Condon](https://sea2.discourse-cdn.com/flex016/user_avatar/devforum.zoom.us/michael_condon/32/13543_2.png) [@Michael\_Condon](https://devforum.zoom.us/u/Michael_Condon)\ **Post date:** [November 2, 2021, 10:48pm UTC](https://devforum.zoom.us/t/c-sdk-remove-cb-onuserleft-not-triggering-at-random/59518/8 "2021-11-02T22:48:00Z")
Hey @bragma, Can you reproduce the issue once more then send me an email to [DeveloperSupport@zoom.us](mailto:DeveloperSupport@zoom.us) with the following info: 1. Reproduction steps 2. SDK logs 3. A link to this post 4. Mention my name Thanks! Michael ---
**Author:** ![bragma](https://sea2.discourse-cdn.com/flex016/user_avatar/devforum.zoom.us/bragma/32/4213_2.png) [@bragma](https://devforum.zoom.us/u/bragma)\ **Post date:** [November 3, 2021, 8:47am UTC](https://devforum.zoom.us/t/c-sdk-remove-cb-onuserleft-not-triggering-at-random/59518/9 "2021-11-03T08:47:49Z")
Sure I can. No problem in giving you the log. The problem is that I have not been able to test the demo app, so at the moment I found the problem only on our app. To enable SKD internal logs, it is this correct (i.e. enable\_log = true)? ```auto var res = sdk.Initialize(new InitParam { enable_log = true, web_domain = "https://zoom.us", config_opts = new ConfigurableOptions { optionalFeatures = (1 << 5) } }); ``` Thanks! ---
**Author:** ![Michael\_Condon](https://sea2.discourse-cdn.com/flex016/user_avatar/devforum.zoom.us/michael_condon/32/13543_2.png) [@Michael\_Condon](https://devforum.zoom.us/u/Michael_Condon)\ **Post date:** [November 4, 2021, 10:45pm UTC](https://devforum.zoom.us/t/c-sdk-remove-cb-onuserleft-not-triggering-at-random/59518/10 "2021-11-04T22:45:54Z")
Hey @bragma, Yep that is correct, the logs should then show up in %appdata%/roaming/zoomsdk. Thanks! Michael ---
**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:** [December 5, 2021, 8:46am UTC](https://devforum.zoom.us/t/c-sdk-remove-cb-onuserleft-not-triggering-at-random/59518/11 "2021-12-05T08:46:26Z")
Closed on December 5, 2021, 8:46am UTC This topic was automatically closed 30 days after the last reply. New replies are no longer allowed.