Unfortunately,openHAB has stopped while open the openHAB application in Android Mobile or Emulator

I am trying to successfully build the apk file in android studio v (1.5.1).In android studio will using the Android version 5.0.1(API 21).I have some adding code in mobile:build.grale file.We are adding the code is
defaultConfig
{
multiDexEnabled true
}.
The below screen shot my build.gradle file.


When ever we will launch the application i getting some error .Error name is “Unfortunately,openHAB has stopped”. The below screen shot during launch the application .My apk file size is 4.3 MB according to project stucture your apk file size is 4.0 MB.how can do slove this issue.Please kindly reply sir.,we will wait for your respose sir.My System Environments:
OS: Fedora 22.
RAM: 4 GB.
JAVA version : JDK 1.8.
Android studio Configurations:
Studio version: Android studio (v1.5.1)
API level:21
Android OS: Version 5.01

@belovictor, any help on this issue ?