black screen in android nougat :(

android {
    compileSdkVersion 26
    buildToolsVersion '26.0.0'
    useLibrary 'org.apache.http.legacy'

    defaultConfig {
        applicationId "com.example.app"
        minSdkVersion 15
        targetSdkVersion 26
        versionCode 8
        versionName "1.0.6"
        multiDexEnabled true
    }
    buildTypes {
        release {
            minifyEnabled true
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }