# joinSession Event callbacks are not fired **URL:** \ **Category:** Windows\ **Created:** [February 16, 2021, 5:28am UTC](https://devforum.zoom.us/t/joinsession-event-callbacks-are-not-fired/43426 "2021-02-16T05:28:14Z")\ **Posts on this page:** 16\ **Page:** 1
**Author:** ![mtaha](https://sea2.discourse-cdn.com/flex016/user_avatar/devforum.zoom.us/mtaha/32/17373_2.png) [@mtaha](https://devforum.zoom.us/u/mtaha)\ **Post date:** [February 16, 2021, 5:28am UTC](https://devforum.zoom.us/t/joinsession-event-callbacks-are-not-fired/43426/1 "2021-02-16T05:28:14Z")
**Description** Using Fully customizable Windows SDK, not getting callback events of joinSession even though joinSession returns Success but not getting onSessionJoin callback. **Error** Error: Send error, 10051 Unknown error Error: Send error, 10051 Unknown error Error: Send error, 10051 Unknown error **Which version?** zoom-instant-sdk-windows-1.0.1 **To Reproduce** Steps to reproduce the behavior: 1. Create console application on Windows(in Visual Studio 2017) using the Fully Customizable SDK 2. Follow [https://marketplace.zoom.us/docs/sdk/custom/windows/essential/initialize](https://marketplace.zoom.us/docs/sdk/custom/windows/essential/initialize) to initialize, register callbacks and then call joinSession api. 3. You will get joinSession api success but no callback events will trigger like onSessionJoin is not called. **Screenshots** I ![image](https://us1.discourse-cdn.com/flex016/uploads/zoomdeveloper/original/3X/2/5/2515e5855c010e3cf672035224305b845a0995d5.png) **Device (please complete the following information):** - Windows 10 ---
**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:** [February 17, 2021, 8:24pm UTC](https://devforum.zoom.us/t/joinsession-event-callbacks-are-not-fired/43426/2 "2021-02-17T20:24:12Z")
Hey @mtaha, Thank you for using the dev forum! Can you provide an example of your JWT payload? Please omitt your key and secret. Thanks! Michael ---
**Author:** ![mtaha](https://sea2.discourse-cdn.com/flex016/user_avatar/devforum.zoom.us/mtaha/32/17373_2.png) [@mtaha](https://devforum.zoom.us/u/mtaha)\ **Post date:** [February 18, 2021, 2:55am UTC](https://devforum.zoom.us/t/joinsession-event-callbacks-are-not-fired/43426/3 "2021-02-18T02:55:03Z")
Hi Michael, JWT payload: { “app\_key”: “###########################”, “version”: 1, “user\_identity”: “Taha39”, “iat”: 1613556600, “exp”: 1613643000, “tpc”: “Testing” } ---
**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:** [February 18, 2021, 8:42pm UTC](https://devforum.zoom.us/t/joinsession-event-callbacks-are-not-fired/43426/4 "2021-02-18T20:42:58Z")
Hey @mtaha, I have tested the SDK with your payload and saw the app hang as well. When I changed the iat and exp values the app behaved normally. Try using the current timestamp at [epochconverter.com](http://epochconverter.com) for iat and a timestamp 24 hours in the future from [epochconverter.com](http://epochconverter.com) for exp. Michael ---
**Author:** ![mtaha](https://sea2.discourse-cdn.com/flex016/user_avatar/devforum.zoom.us/mtaha/32/17373_2.png) [@mtaha](https://devforum.zoom.us/u/mtaha)\ **Post date:** [February 19, 2021, 3:05am UTC](https://devforum.zoom.us/t/joinsession-event-callbacks-are-not-fired/43426/5 "2021-02-19T03:05:28Z")
Tried same [epochconverter.com](http://epochconverter.com) date with 24 hours timestamp but still not getting event callback. ---
**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:** [February 19, 2021, 10:33pm UTC](https://devforum.zoom.us/t/joinsession-event-callbacks-are-not-fired/43426/6 "2021-02-19T22:33:52Z")
Hey @mtaha, Interesting. Let me investigate this further. Michael ---
**Author:** ![mtaha](https://sea2.discourse-cdn.com/flex016/user_avatar/devforum.zoom.us/mtaha/32/17373_2.png) [@mtaha](https://devforum.zoom.us/u/mtaha)\ **Post date:** [February 22, 2021, 4:32am UTC](https://devforum.zoom.us/t/joinsession-event-callbacks-are-not-fired/43426/7 "2021-02-22T04:32:45Z")
Please try that on Windows 10 with Visual Studio 2019 and with same Zoom FC SDK… ---
**Author:** ![hung](https://sea2.discourse-cdn.com/flex016/user_avatar/devforum.zoom.us/hung/32/22250_2.png) [@hung](https://devforum.zoom.us/u/hung)\ **Post date:** [February 23, 2021, 4:04am UTC](https://devforum.zoom.us/t/joinsession-event-callbacks-are-not-fired/43426/8 "2021-02-23T04:04:26Z")
Hi @Michael_Condon, I can confirm I am also seeing this **Error** Error: Send error, 10051 Unknown error Error: Send error, 10051 Unknown error Error: Send error, 10051 Unknown error **To Reproduce** 1. Create Console Application, but on Visual Studio 2019 with the Fully Customizable SDK. 2. Create `ZoomInstantSDKInitParams` based on the instructions, and call initialize. I did NOT attempt to even join any session yet. 3. Despite initialize returning success, I get the 10051 error also (also 3 times.) **Additional Debugging** - I made sure that the built exe application had access through the firewall. - I tried the SDK NOT on a Console test application and it DID work (including the onSessionJoin callback), so I suspect it’s an SDK error with the Console. - `IZoomInstantSDK->isInSession() == false` even if `joinSession() != NULL` ---
**Author:** ![mtaha](https://sea2.discourse-cdn.com/flex016/user_avatar/devforum.zoom.us/mtaha/32/17373_2.png) [@mtaha](https://devforum.zoom.us/u/mtaha)\ **Post date:** [February 23, 2021, 5:36am UTC](https://devforum.zoom.us/t/joinsession-event-callbacks-are-not-fired/43426/9 "2021-02-23T05:36:51Z")
Hi @ hung, Thanks for the information. I believe Zoom Fully Customizable SDK will resolve this issue with Console application soon. I have also tried with Windows Application(NOT console) and callbacks are working now. Thanks again for your support. ---
**Author:** ![jon.zoom](https://sea2.discourse-cdn.com/flex016/user_avatar/devforum.zoom.us/jon.zoom/32/13495_2.png) [@jon.zoom](https://devforum.zoom.us/u/jon.zoom)\ **Post date:** [February 23, 2021, 9:57pm UTC](https://devforum.zoom.us/t/joinsession-event-callbacks-are-not-fired/43426/10 "2021-02-23T21:57:44Z")
Hi @hung and @mtaha, thanks for the additional information. We will take this into account as we continue to investigate this issue. Once we have any updates, we will be sure to reach out. Thanks! ---
**Author:** ![mtaha](https://sea2.discourse-cdn.com/flex016/user_avatar/devforum.zoom.us/mtaha/32/17373_2.png) [@mtaha](https://devforum.zoom.us/u/mtaha)\ **Post date:** [February 24, 2021, 4:34am UTC](https://devforum.zoom.us/t/joinsession-event-callbacks-are-not-fired/43426/11 "2021-02-24T04:34:03Z")
The console application need a **Message Loop** so that messages can be delivered to the correct procedure. The application needs a loop to retrieve the messages and dispatch them to the correct windows. So I have implement this Message Loop in my console application and my console application is also working now. Use below message loop in main function of Console Application to make it work: bool bRet = false; MSG msg; while ((bRet = GetMessage(&msg, nullptr, 0, 0)) != 0) { if (bRet == -1) { // handle the error and possibly exit } else { TranslateMessage(&msg); DispatchMessage(&msg); } } ---
**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:** [February 24, 2021, 7:30pm UTC](https://devforum.zoom.us/t/joinsession-event-callbacks-are-not-fired/43426/12 "2021-02-24T19:30:13Z")
Hey @mtaha, That makes a lot of sense! Thank you for providing this. @hung Can you see if what @mtaha said works in your situation as well? Thanks! Michael ---
**Author:** ![hung](https://sea2.discourse-cdn.com/flex016/user_avatar/devforum.zoom.us/hung/32/22250_2.png) [@hung](https://devforum.zoom.us/u/hung)\ **Post date:** [February 26, 2021, 6:07am UTC](https://devforum.zoom.us/t/joinsession-event-callbacks-are-not-fired/43426/13 "2021-02-26T06:07:36Z")
I am getting my callbacks in the console now, but still receiving Error: Send error, 10051 Unknown error (x3) I think that the error message is unrelated to the Message Loop issue, @mtaha can you confirm the 10051 error messages are still there for you? ---
**Author:** ![mtaha](https://sea2.discourse-cdn.com/flex016/user_avatar/devforum.zoom.us/mtaha/32/17373_2.png) [@mtaha](https://devforum.zoom.us/u/mtaha)\ **Post date:** [February 26, 2021, 6:10am UTC](https://devforum.zoom.us/t/joinsession-event-callbacks-are-not-fired/43426/14 "2021-02-26T06:10:49Z")
> [@hung](#): > > Send error, 10051 Unknown error (x3) Basically, Send error, 10051 Unknown error (x3) this error is somewhere from Zoom SDK. I am saying so because I can see that console error in Zoom FC-SDK Electron sample console also. ---
**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:** [February 26, 2021, 6:11pm UTC](https://devforum.zoom.us/t/joinsession-event-callbacks-are-not-fired/43426/15 "2021-02-26T18:11:03Z")
Hey @mtaha and @hung, Interesting, I will inform the team of this. 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:** [March 29, 2021, 4:11am UTC](https://devforum.zoom.us/t/joinsession-event-callbacks-are-not-fired/43426/16 "2021-03-29T04:11:25Z")
Closed on March 29, 2021, 4:11am UTC This topic was automatically closed 30 days after the last reply. New replies are no longer allowed.