Failed to parse altool outpoot while Uploading Xamarin.iOS app to App Store Connect

I developed an app using Xamarin Forms and visual studio on macbook. When I tried to upload the app to App Store Connect, I get an error saying "Failed to parse altool outpoot: Failed to parse PList data type: Output: altool[5527:86472] Error:Error Could not find or load main class.  I hope you guys can help me figuring out this issue here. Thank you very much in advance!
When using 3rd party tools/SDKs, it can be more helpful to seek support from the authors of those products, vs. devForums which are Apple IDE-centric, thanks and good luck.
Failed to parse altool outpoot while Uploading Xamarin.iOS app to App Store Connect
 
 
Q