C# wrapper demo client authorization callback not being called

When I attempt to run the demo app the OnAuthenticationReturn callback is never called. After clicking the Auth button in MainWindow.xaml. It hides and there is no further action.

The MessageBox I placed to check for activity, is never shown.

 public void OnAuthenticationReturn(AuthResult ret)
            if (ZOOM_SDK_DOTNET_WRAP.AuthResult.AUTHRET_SUCCESS == ret)
            else//error handle.todo


Which Windows Client SDK version?
C# wrapper v5.5.12511.0422

To Reproduce(If applicable)
Steps to reproduce the behavior:
1.Download C# wrapper C# wrapper v5.5.12511.0422
2. Open \zoom_sdk_demo\zoom_sdk_demo.csproj
3. Change project configuration to Release, change platform to x86.
4. Click Start (in Visual Studio)
5. MainWindow.xaml is shown.
6. Input token and Click Auth
7. Window disappears and there is no other activity, however the program does remain running.


  • Device: Ryzen desktop
  • OS: Windows 10
    Microsoft Visual Studio Community 2019
    Version 16.9.4

Hi @juanricos, thanks for using our SDK.

Can you please provide the contents of your JWT with all credentials redacted?


OK, here is one I generated with a fake key and secret.


I have the same problem.

I used the JWT I generated in the C++ demo app(\zoom-sdk-windows-5.5.12511.0422\bin\sdk_demo_v2.exe). It authenticated successfully at that time.
I used the same JWT in the C# demo app in Visual Studio 2019 within a minute. And then, the OnAuthenticationReturn callback was not called. My project configuration is Release / x86.

Hi @j-ishii and @juanricos,

So it does seem like you both are using the correct JWT format. The next step would be to check that all of the SDK files have been correctly added to the project. Can you please confirm that you are following the steps listed out in our documentation here precisely?


Thank you for the reply.

Originally, I did not do that folder rearranging because of what I read here: Windows SDK Demo dosn't work - #4 by Michael_Condon

Michael_Condon writes " No need to move files over from the C++ SDK."

But I did try to follow the instructions today and it just leads to numerous errors when building the project. So it does seem that those instructions are indeed outdated.

With the project as downloaded, it builds and runs fine, just no OnAuthenticationReturn callback.

I also downloaded latest Windows C# SDK and getting same behaviour. Nothing happen after entering token, callback not invoked.

Previous release v5.5.12509.0330 is working.
v5.5.12511.0422 is broken.

For me, I am seeing identical behavior in v5.5.12509.0330 and v5.5.12511.0422, No callback after entering token.

I was able to solve this problem.


  1. Unzip zoom-c-sharp-wrapper-5.5.12511.0422.zip (Start with a clean sln)
  2. Open the file zoom_sdk_c_sharp_wrap.sln in VisualStudio
  3. Change project configuration to Release, change platform to x86
  4. Build the solution
  5. Right-click on “zoom_sdk_demo” in the Solution Explorer after the build is finished
  6. Click “Set as StratUp Project”
  7. Click Start (in Visual Studio)
  8. MainWindow.xaml is shown
  9. Input token and Click Auth

The guide says “Open the demo project by clicking zoom_sdk_demo.csproj”, but I started the demo with the sln file open.

My development environment is as follows
・Windows 10
・Microsoft Visual Studio Professional 2019 Version 16.9.4
・C# wrapper v5.5.12511.0422

1 Like

That worked, thank you.

Thank you @j-ishii, for sharing the solution that worked for you!

Please don’t hesitate to reach back out in a new thread with any additional questions. :slightly_smiling_face:

Worked for me too.

Means first we need to compile and generate new wrapper binary. Pre-compiled binary that comes with zip will not work.

Good catch @j-ishii

Glad to hear their solution worked for you as well!

Hi, I also have this problem, but this doesn’t work for me

Hey @Takabrycheri,

Can you start a new thread with details about the issue you are facing so that we can assist you?