generate signed apk is not working, apk is unsigned

Question

I used to generate a signed apk from Android Studio and everything was working well until I updated Android Studio to 3.3. It generates an apk but after I try to install it, it says: App Not Installed!

My Trial was by:

1. Click on build
2. Generate Signed Apk
3. Choose APK and click Next
4. Insert the Key Store Path, Key Store Password, Key Alias, Key Password
5. Click Next
6. Choose Release Variant
7. Click Finish

The Apk is generated but it's not signed! What is the problem ?

Here is my app build.gradle

buildscript {
    repositories {
        maven { url 'https://maven.fabric.io/public' }
    }

    dependencies {
        classpath 'io.fabric.tools:gradle:1.+'
    }
}
apply plugin: 'com.android.application'
apply plugin: 'io.fabric'

repositories {
    maven { url 'https://maven.fabric.io/public' }
}


android {
    useLibrary 'org.apache.http.legacy'
    compileSdkVersion 27
    defaultConfig {
        applicationId "com.twobreathe.soft2breathe"
        minSdkVersion 23
        targetSdkVersion 27
        versionCode 9
        versionName "1.1"
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
        externalNativeBuild {
            cmake {
                cppFlags ""
            }
        }
        vectorDrawables {
            useSupportLibrary true
        }
        resConfigs "en", "ja"
    }
    signingConfigs {
        release {
            keyAlias "[my key alias]"
            keyPassword "[my key password]"
            storeFile file("[path to the keystore file]")
            storePassword "[my store password]"
        }
    }

    buildTypes {
        release {
            minifyEnabled true
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
            shrinkResources true
            pseudoLocalesEnabled false
        }

        debug {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
            debuggable true
        }


    }
    externalNativeBuild {
        cmake {
            path "src/main/cpp/fluidsynth/android/CMakeLists.txt"
        }
    }
    lintOptions {
        checkReleaseBuilds false
        abortOnError false
    }
    dataBinding {
        enabled true
    }
    compileOptions {
        sourceCompatibility JavaVersion.VERSION_1_8
        targetCompatibility JavaVersion.VERSION_1_8
    }
    buildToolsVersion '28.0.3'
    productFlavors {
    }
}

dependencies {
    implementation fileTree(include: ['*.jar'], dir: 'libs')
    implementation 'com.android.support:appcompat-v7:27.1.1'
    implementation 'com.android.support.constraint:constraint-layout:1.1.3'
    implementation 'com.github.parse-community.Parse-SDK-Android:parse:1.18.4'
    implementation 'com.jjoe64:graphview:4.2.2'
    implementation 'io.reactivex.rxjava2:rxjava:2.2.0'
    implementation 'io.reactivex.rxjava2:rxandroid:2.1.0'
    testImplementation 'junit:junit:4.12'
    implementation 'com.orhanobut:hawk:2.0.1'
    implementation 'xyz.sahildave:arclayout:1.0.0'
    implementation 'com.mikhaellopez:circularprogressbar:2.0.0'
    androidTestImplementation 'com.android.support.test:runner:1.0.2'
    implementation 'com.github.GrenderG:Toasty:1.3.0'
    implementation 'com.kyleduo.switchbutton:library:2.0.0'
    implementation 'com.github.franmontiel:LocaleChanger:0.9.2'
    implementation 'cn.aigestudio.wheelpicker:WheelPicker:1.1.2'
    androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'
    implementation 'com.crashlytics.sdk.android:crashlytics:2.9.8'
}

Answer 1

After updating to 3.3, many problems are occuring related to signing an APK. Sometime it doesn't sign the apk and sometime it says the key is not private.

Well i also faced this problem after upgrading to android studio 3.3 and i resolved in 3 steps. But firstly make sure you backup your whole project.

1. In Android Studio goto File > Project Structure and untick from "use embedded JDK" then click OK
2. Goto Computer Settings (system settings) (win + pause key) then go to Advanced system settings>Environment variables. if JAVA_HOME not present then add it and set path to your installed JDK.
   As i couldn't find a direct approach to modify jdk path in my project that is upgraded in some way to android studio 3.3 settings, i did following(for the last step) BUT MAKE SURE YOU MAKE BACKUP BEFORE THIS.
3. To make sure where i am guiding come to project view, I deleted ".grade", ".idea", "capture", "gradle" folders from the root and "build", "release", "lib" folder from "app" leaving "src" as it is. Deleted root.iml and did not delete app.iml file Then rebuild the project and then created the Signed package.

It went successful after 2 try. To be very honest i did the last step twice by restoring files from backup. As deleting these folders i messed up 1 time.