Sik Telemetry Issue

Hello Guys,

I have just build my quad with pixhawk 2.1, Unmanned Tech 500 mW telemetry and QGC software. But whenever i connect the pixhawk to qgc via telemetry, some buttons in vehicle setup tab are missing. There are just “summary”, “firmware”, and “parameters”. And it writes after complete connection (green bars is fullfilled) “qgc was unable to retrive full set of parameters from vehicle 1…”

What do you think about the possible reasons of that?

Thank you.