Error _504 or error - 108 appears when app is downloaded from Google PlayStore ..What can be causes of this errors in the code?

Question

Error -504 or error - 108 appears when app is downloaded from playstore. I have worked hard for about an year and created an app.Signed it and uploaded it to playstore as Beta.I have debugged and tested the app - the app appears to work well.6/10 people were able to install the app and run it.But on remaining devices the app store shows error code - 504 and error code- 108. In my gradle I gave support to a lot of devices with minSdk as low as 15. The app appears to work fine in android 7.1 of one devices.But other devices with same android version and configs...are showing error during installation ..or download..!(code-504 / code -108) Can these error appear due to my gradle or mainifest files..?

here is snippet of my files:-

build.gradle(project)

// Top-level build file where you can add configuration options common to all sub-projects/modules.

buildscript {
    
    repositories {
        google()
        jcenter()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:3.1.2'
        classpath 'com.google.gms:google-services:3.2.0'
        

        // NOTE: Do not place your application dependencies here; they belong
        // in the individual module build.gradle files
    }
}

allprojects {
    repositories {
        google()
        jcenter()
        maven { url "https://jitpack.io" }
        maven { url "https://maven.google.com" }
    }
}

task clean(type: Delete) {
    delete rootProject.buildDir
}

build.gradle (Module)

apply plugin: 'com.android.application'

android {
    compileSdkVersion 27
    defaultConfig {
        applicationId "com.backbenchers.administrator.instaclone"
        minSdkVersion 15
        targetSdkVersion 27
        versionCode 2
        versionName "1.1"
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
}

dependencies {
    implementation fileTree(dir: 'libs', include: ['*.jar'])
    implementation 'com.android.support:appcompat-v7:27.0.2'
    implementation 'com.android.support:design:27.0.2'
    implementation 'com.android.support.constraint:constraint-layout:1.0.2'
    testImplementation 'junit:junit:4.12'
    androidTestImplementation 'com.android.support.test:runner:1.0.1'
    androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.1'

    //firebase core
    implementation 'com.google.firebase:firebase-core:10.2.6'

    //bottom navigation view lib
    implementation 'com.github.ittianyu:BottomNavigationViewEx:1.2.4'

    //circle image view
    implementation 'de.hdodenhof:circleimageview:2.2.0'

    //universal image loader
    implementation 'com.nostra13.universalimageloader:universal-image-loader:1.9.5'

    //firebase authentication
    implementation 'com.google.firebase:firebase-auth:10.2.6'

    //firebase realtime database
    implementation 'com.google.firebase:firebase-database:10.2.6'

    //firebase storage
    implementation 'com.google.firebase:firebase-storage:10.2.6'



    //recycler view
    implementation 'com.android.support:recyclerview-v7:27.0.2'

    //cardview
    implementation 'com.android.support:cardview-v7:27.0.2'



    //custom tabs chrome lib
    implementation 'com.android.support:customtabs:27.0.2'

    //play services auth
    implementation 'com.google.android.gms:play-services-identity:10.2.6'
    implementation 'com.google.android.gms:play-services-auth:10.2.6'


///there are more library implemetations...


    //youtube api
    implementation files('libs/YouTubeAndroidPlayerApi.jar')

}

///Firebase
apply plugin: 'com.google.gms.google-services'

Manifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    package="com.backbenchers.administrator.instaclone">

    <uses-permission android:name="android.permission.INTERNET" />
    <uses-permission android:name="android.permission.CAMERA" />
    <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

    <uses-sdk android:minSdkVersion="15" android:targetSdkVersion="27" />

    <application
        android:name=".Utils.FirebaseOffline"
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity android:name=".Register.NewRegisterActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        
        
        .....all other activities used in the app...remains here

the error is not due to some problem in catch or settings of these devices..I think something is wrong in the code..

please help me know the potential reasons in the code that can cause these errors...!...im lost....!

Answer 1

I later found the solution to the problem. It was due to having "Uppercase" letters when naming packages inside the java folder. It was not showing any parsing or Error -504 or error - 108 in android version N or higher. But the package was not able to install properly in android version lower than N. The problem is that android studio never shows a warning when naming packages in java folder.. like it does in naming resources ALWAYS NAME PACKAGES INSIDE JAVA FOLDER IN lowercase*