Mavlink crashes after trying to call «Arm» command

[Harvester-76]

When I call drone.arm() it completes with an error. After command completion in my «onError» callback I have the next error

«The operation couldn’t be completed. (MAVSDK_Swift.Action.ActionError error 1.)»

After that my application crashes in another thread in binary file (90% that it happens somewhere inside SDK) so that I can’t even understand where exactly it happens. I suppose that there might be some problem in Mavlink communication with the drone but I need to understand what exactly happens and what seems to be wrong for SDK to work correctly.