Generally an error like that is caused by inappropriate manifest file. Please check at the top of the document about setting permission.
<manifest ... >
<uses-permission android:name="android.permission.BLUETOOTH" />
...
</manifest>
If you have done that and still getting the error, it means that your emulator is not setup properly to use your System's bluetooth. You can just debug the App, copy the .apk in bin folder in your phone/tab and install it there. Test the app in real device.