Install and run Android in Androidx86 emulator

I try to install Androidx86 emulator via VirtualBox (host computer uses windows 7) .

I use Androidx86 emulator to launch my application that applyes bluetooth. In host PC I have usb bluetooth dongle for it. I need test my application (uses bluetooth) with different screen sizes that's why I use Androidx86.

Everything went well. I install Androidx86 on virtual box. After that I set bluetooth so that bluetooth in virtualBox uses usb bluetooth dongle on host machine.

Next task was install my application from Android Studio to Androidx86 emulator.In command line of Androidx86 I typed commands:

setprop service.adb.tcp.port 5555

stop adbd

start adbd

From settings -> about tablet -> status -> ip address I knew IP ofAndroidx86.

In my host PC (windows 7) from next path (where SDK located)

C:AndroidSDKplatform-tools

I typed commands:

adb kill-server

adb connect 192.168.250.116:5555

Than I tried to run Android Studio and saw Androidx86 emulator. But it was offline. When I tried to build and load my application to **Androidx86* emulator I got next error in Android Studio:

com.android.ddmlib.AdbCommandRejectedException: device unauthorized.

This adb server's $ADB_VENDOR_KEYS is not set

Try 'adb kill-server' if that seems wrong.

Otherwise check for a confirmation dialog on your device.

Error while Installing APK

I repeated this commands

adb kill-server

adb connect 192.168.250.116:5555

But it didn't help me.

How can I solve this problem ?

How can I authorize device and set $ADB_VENDOR_KEYS ?