Error when connecting with real UAV

[X-DDDDD]

Hello, Your project is great.I'm trying to use your project to connect to a real UAV, but the following error occurred:

NullReferenceException: Object reference not set to an instance of an object
UnityControllerForTello.SceneManager.RunFrame () (at Assets/Scripts/UnityTelloController/SceneManager.cs:174)

Why did this error occur? Looking forward to your reply, thank you.😁

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I switched the TELLOTRACKING scenario, it can be running.But there will be a problem, https://github.com/comoc/TelloForUnity/issues/12. I noticed that the computer is transmitting at the speed of 500K per second from Tello, but it can't receive the image. Why is this? thank you.😁