Android Studio recognizes physical Device as Null?

I've been developing an Android Application for Android (SDK min version 14) and I have testing it normally with tablets such as Samsung Galaxy 2 and Nexus 7. However when I tried to run the application (by clicking run in AndroidStudio), AS does not recognise the tablet information, which is shown in the picture below.

The interesting thing is that as shown in the picture above, AS is also detecting the device sdk as API 1 when it's Android version is 4.2.2 The tablet is already set to accept "USB debugging" in the developer options, I'have tried rebooting the tablet, and restarting AS, but still I get the same problem(everything is fine with nexus 7 and Samsung Galaxy 2).

The tablet/device I'm working on is a "VeryKool" T742

Environment information:
 OS: ubuntu
 AndroidStudio version: 0.8.6

 Tablet Android version:4.2.2
 Tablet Kernel version: 3.4.5
 App min SDK: 14

Solution 1:

Ok So I finally found the problem, apparently on this device you have to set to connect as camera(even after usb debugging is already enabled)

Also this link describes the setting up process

Solution 2:

I've seen this error a few times when adb hasn't been connected with correct permissions.

On the terminal try

~/Android/Sdk/platform-tools> ./adb devices    

if it returns

<deviceIdentifier> no permissions

then you need to restart adb with correct perms

~/Android/Sdk/platform-tools$> ./adb kill-server
~/Android/Sdk/platform-tools$> sudo ./adb devices

if that worked then you'll get

List of devices attached
* daemon not running. starting it now on port 5037 *
* daemon started successfully *
<deviceIdentifier>  device

No more Sdk version resolution issues in Android Studio after that.

Solution 3:

Just run this command after you connect your device to your Ubuntu system:

adb devices

This works for me.

Note: Make sure you have selected file transfer option in your phone.

Solution 4:

On Ubuntu, with my Pixel XL on 8.0, I had to do this while plugged into computer:

Settings -> Connected Devices -> USB --> Change to 'Transferring Files'