Unsigned Generated APK not working on Android Device

Developed an unsigned APK,ran it through USB Debugging worked fine and ran the same transferring the APK file to an Android Phone(Oreo)it gets installed but doesn't open up(However many times i tap on the "Open" Button)
[Minimum SDK Version of APK is "Ice Cream Sandwich"]

Things I Tried:

• Uninstalled the application,Cleared all App Data;Reinstalled(from File Manager) still didn't opened.
• Made sure that "Install from unknown sources was enabled".
• Installed the application on my friend's Android device still didn't opened.
• Uninstalled application from PC through adb shell pm uninstall com.example.seve, Reinstalled still didn't opened.
• Made sure Google Play Protect was disabled.

2019-10-10 19:52:07.241 28262-28262/? E/GlobalPackageInstaller: launchApp error:
    java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String android.content.Intent.toString()' on a null object reference
        at android.app.Instrumentation.execStartActivity(Instrumentation.java:1582)
        at android.app.Activity.startActivityForResult(Activity.java:4555)
        at android.app.Activity.startActivityForResult(Activity.java:4513)
        at android.app.Activity.startActivity(Activity.java:4874)
        at android.app.Activity.startActivity(Activity.java:4842)
        at com.miui.global.packageinstaller.GlobalPackageInstallerActivity.g(Unknown Source:14)
        at com.miui.global.packageinstaller.GlobalPackageInstallerActivity.onClick(Unknown Source:77)
        at android.view.View.performClick(View.java:6304)
        at android.view.View$PerformClick.run(View.java:24803)
        at android.os.Handler.handleCallback(Handler.java:794)
        at android.os.Handler.dispatchMessage(Handler.java:99)
        at android.os.Looper.loop(Looper.java:176)
        at android.app.ActivityThread.main(ActivityThread.java:6651)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:547)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:824)

Here are all my files.
MainActivity.java

IntroActivity.java

dash.java

IntroViewPagerAdapter.java

ScreenItem.java


Any suggestion will be appreciated.

EDIT: I found that the error is hidden mainly in my application so, I tried View Breakpoints and got something like this in logcat.Logcat tells that ClassNotFoundException is caused by somewhere around line 19 MainActivity.java but can't make much from it.
I tried disabling instant run got nothing and checked that <activity android:name=".IntroActivity"> is written instead of <activity android:name="android.app.IntroActivity
and enabled MultiDex"

2019-10-12 13:06:59.933 15201-15201/com.example.seve W/ResourceType: No package identifier when getting name for resource number 0x00000000
2019-10-12 13:07:00.100 15201-15201/com.example.seve D/AccessibilityManager: AccessibilityManager status: mPackageName = com.example.seve, mOptimizeEnabled = false, mIsEnabled = false, mIsUiAutomationEnabled = false, mIsInterestedPackage =false
2019-10-12 13:07:00.159 15201-15201/com.example.seve I/zygote64: Rejecting re-init on previously-failed class java.lang.Class<androidx.core.view.ViewCompat$OnUnhandledKeyEventListenerWrapper>: java.lang.NoClassDefFoundError: Failed resolution of: Landroid/view/View$OnUnhandledKeyEventListener;
2019-10-12 13:07:00.160 15201-15201/com.example.seve I/zygote64:     at void androidx.core.view.ViewCompat.setOnApplyWindowInsetsListener(android.view.View, androidx.core.view.OnApplyWindowInsetsListener) (ViewCompat.java:2203)
2019-10-12 13:07:00.160 15201-15201/com.example.seve I/zygote64:     at android.view.ViewGroup androidx.appcompat.app.AppCompatDelegateImpl.createSubDecor() (AppCompatDelegateImpl.java:637)
2019-10-12 13:07:00.160 15201-15201/com.example.seve I/zygote64:     at void androidx.appcompat.app.AppCompatDelegateImpl.ensureSubDecor() (AppCompatDelegateImpl.java:518)
2019-10-12 13:07:00.160 15201-15201/com.example.seve I/zygote64:     at void androidx.appcompat.app.AppCompatDelegateImpl.setContentView(int) (AppCompatDelegateImpl.java:466)
2019-10-12 13:07:00.160 15201-15201/com.example.seve I/zygote64:     at void androidx.appcompat.app.AppCompatActivity.setContentView(int) (AppCompatActivity.java:140)
2019-10-12 13:07:00.160 15201-15201/com.example.seve I/zygote64:     at void com.example.seve.MainActivity.onCreate(android.os.Bundle) (MainActivity.java:19)
2019-10-12 13:07:00.160 15201-15201/com.example.seve I/zygote64:     at void android.app.Activity.performCreate(android.os.Bundle, android.os.PersistableBundle) (Activity.java:7088)
2019-10-12 13:07:00.160 15201-15201/com.example.seve I/zygote64:     at void android.app.Activity.performCreate(android.os.Bundle) (Activity.java:7079)
2019-10-12 13:07:00.160 15201-15201/com.example.seve I/zygote64:     at void android.app.Instrumentation.callActivityOnCreate(android.app.Activity, android.os.Bundle) (Instrumentation.java:1215)
2019-10-12 13:07:00.160 15201-15201/com.example.seve I/zygote64:     at android.app.Activity android.app.ActivityThread.performLaunchActivity(android.app.ActivityThread$ActivityClientRecord, android.content.Intent) (ActivityThread.java:2770)
2019-10-12 13:07:00.160 15201-15201/com.example.seve I/zygote64:     at void android.app.ActivityThread.handleLaunchActivity(android.app.ActivityThread$ActivityClientRecord, android.content.Intent, java.lang.String) (ActivityThread.java:2895)
2019-10-12 13:07:00.160 15201-15201/com.example.seve I/zygote64:     at void android.app.ActivityThread.-wrap11(android.app.ActivityThread, android.app.ActivityThread$ActivityClientRecord, android.content.Intent, java.lang.String) (ActivityThread.java:-1)
2019-10-12 13:07:00.160 15201-15201/com.example.seve I/zygote64:     at void android.app.ActivityThread$H.handleMessage(android.os.Message) (ActivityThread.java:1616)
2019-10-12 13:07:00.160 15201-15201/com.example.seve I/zygote64:     at void android.os.Handler.dispatchMessage(android.os.Message) (Handler.java:106)
2019-10-12 13:07:00.160 15201-15201/com.example.seve I/zygote64:     at void android.os.Looper.loop() (Looper.java:176)
2019-10-12 13:07:00.160 15201-15201/com.example.seve I/zygote64:     at void android.app.ActivityThread.main(java.lang.String[]) (ActivityThread.java:6651)
2019-10-12 13:07:00.160 15201-15201/com.example.seve I/zygote64:     at java.lang.Object java.lang.reflect.Method.invoke(java.lang.Object, java.lang.Object[]) (Method.java:-2)
2019-10-12 13:07:00.160 15201-15201/com.example.seve I/zygote64:     at void com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run() (RuntimeInit.java:547)
2019-10-12 13:07:00.160 15201-15201/com.example.seve I/zygote64:     at void com.android.internal.os.ZygoteInit.main(java.lang.String[]) (ZygoteInit.java:824)
2019-10-12 13:07:00.160 15201-15201/com.example.seve I/zygote64:Caused by: java.lang.ClassNotFoundException: Didn't find class "android.view.View$OnUnhandledKeyEventListener" on path: DexPathList[[zip file "/data/app/com.example.seve-GCOyFEE-ADwenEs5Wnn_ZA==/base.apk", zip file "/data/app/com.example.seve-GCOyFEE-ADwenEs5Wnn_ZA==/split_lib_dependencies_apk.apk", zip file "/data/app/com.example.seve-GCOyFEE-ADwenEs5Wnn_ZA==/split_lib_resources_apk.apk", zip file "/data/app/com.example.seve-GCOyFEE-ADwenEs5Wnn_ZA==/split_lib_slice_0_apk.apk", zip file "/data/app/com.example.seve-GCOyFEE-ADwenEs5Wnn_ZA==/split_lib_slice_1_apk.apk", zip file "/data/app/com.example.seve-GCOyFEE-ADwenEs5Wnn_ZA==/split_lib_slice_2_apk.apk", zip file "/data/app/com.example.seve-GCOyFEE-ADwenEs5Wnn_ZA==/split_lib_slice_3_apk.apk", zip file "/data/app/com.example.seve-GCOyFEE-ADwenEs5Wnn_ZA==/split_lib_slice_4_apk.apk", zip file "/data/app/com.example.seve-GCOyFEE-ADwenEs5Wnn_ZA==/split_lib_slice_5_apk.apk", zip file "/data/app/com.example.seve-GCOyFEE-ADwenEs5Wnn_ZA==/split_lib_slice_6_apk.apk", 
2019-10-12 13:07:00.160 15201-15201/com.example.seve I/zygote64:     at java.lang.Class dalvik.system.BaseDexClassLoader.findClass(java.lang.String) (BaseDexClassLoader.java:125)
2019-10-12 13:07:00.160 15201-15201/com.example.seve I/zygote64:     at java.lang.Class java.lang.ClassLoader.loadClass(java.lang.String, boolean) (ClassLoader.java:379)
2019-10-12 13:07:00.160 15201-15201/com.example.seve I/zygote64:     at java.lang.Class java.lang.ClassLoader.loadClass(java.lang.String) (ClassLoader.java:312)
2019-10-12 13:07:00.160 15201-15201/com.example.seve I/zygote64:     at void androidx.core.view.ViewCompat.setOnApplyWindowInsetsListener(android.view.View, androidx.core.view.OnApplyWindowInsetsListener) (ViewCompat.java:2203)
2019-10-12 13:07:00.160 15201-15201/com.example.seve I/zygote64:     at android.view.ViewGroup androidx.appcompat.app.AppCompatDelegateImpl.createSubDecor() (AppCompatDelegateImpl.java:637)
2019-10-12 13:07:00.160 15201-15201/com.example.seve I/zygote64:     at void androidx.appcompat.app.AppCompatDelegateImpl.ensureSubDecor() (AppCompatDelegateImpl.java:518)
2019-10-12 13:07:00.160 15201-15201/com.example.seve I/zygote64:     at void androidx.appcompat.app.AppCompatDelegateImpl.setContentView(int) (AppCompatDelegateImpl.java:466)
2019-10-12 13:07:00.160 15201-15201/com.example.seve I/zygote64:     at void androidx.appcompat.app.AppCompatActivity.setContentView(int) (AppCompatActivity.java:140)
2019-10-12 13:07:00.160 15201-15201/com.example.seve I/zygote64:     at void com.example.seve.MainActivity.onCreate(android.os.Bundle) (MainActivity.java:19)
2019-10-12 13:07:00.160 15201-15201/com.example.seve I/zygote64:     at void android.app.Activity.performCreate(android.os.Bundle, android.os.PersistableBundle) (Activity.java:7088)
2019-10-12 13:07:00.160 15201-15201/com.example.seve I/zygote64:     at void android.app.Activity.performCreate(android.os.Bundle) (Activity.java:7079)
2019-10-12 13:07:00.160 15201-15201/com.example.seve I/zygote64:     at void android.app.Instrumentation.callActivityOnCreate(android.app.Activity, android.os.Bundle) (Instrumentation.java:1215)
2019-10-12 13:07:00.160 15201-15201/com.example.seve I/zygote64:     at android.app.Activity android.app.ActivityThread.performLaunchActivity(android.app.ActivityThread$ActivityClientRecord, android.content.Intent) (ActivityThread.java:2770)
2019-10-12 13:07:00.160 15201-15201/com.example.seve I/zygote64:     at void android.app.ActivityThread.handleLaunchActivity(android.app.ActivityThread$ActivityClientRecord, android.content.Intent, java.lang.String) (ActivityThread.java:2895)
2019-10-12 13:07:00.160 15201-15201/com.example.seve I/zygote64:     at void android.app.ActivityThread.-wrap11(android.app.ActivityThread, android.app.ActivityThread$ActivityClientRecord, android.content.Intent, java.lang.String) (ActivityThread.java:-1)
2019-10-12 13:07:00.160 15201-15201/com.example.seve I/zygote64:     at void android.app.ActivityThread$H.handleMessage(android.os.Message) (ActivityThread.java:1616)
2019-10-12 13:07:00.160 15201-15201/com.example.seve I/zygote64:     at void android.os.Handler.dispatchMessage(android.os.Message) (Handler.java:106)
2019-10-12 13:07:00.160 15201-15201/com.example.seve I/zygote64:     at void android.os.Looper.loop() (Looper.java:176)
2019-10-12 13:07:00.160 15201-15201/com.example.seve I/zygote64:     at void android.app.ActivityThread.main(java.lang.String[]) (ActivityThread.java:6651)
2019-10-12 13:07:00.160 15201-15201/com.example.seve I/zygote64:     at java.lang.Object java.lang.reflect.Method.invoke(java.lang.Object, java.lang.Object[]) (Method.java:-2)
2019-10-12 13:07:00.160 15201-15201/com.example.seve I/zygote64:     at void com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run() (RuntimeInit.java:547)
2019-10-12 13:07:00.160 15201-15201/com.example.seve I/zygote64:     at void com.android.internal.os.ZygoteInit.main(java.lang.String[]) (ZygoteInit.java:824)
2019-10-12 13:07:00.161 15201-15201/com.example.seve I/zygote64: Rejecting re-init on previously-failed class java.lang.Class<androidx.core.view.ViewCompat$OnUnhandledKeyEventListenerWrapper>: java.lang.NoClassDefFoundError: Failed resolution of: Landroid/view/View$OnUnhandledKeyEventListener;
2019-10-12 13:07:00.161 15201-15201/com.example.seve I/zygote64:     at void androidx.core.view.ViewCompat.setOnApplyWindowInsetsListener(android.view.View, androidx.core.view.OnApplyWindowInsetsListener) (ViewCompat.java:2203)
2019-10-12 13:07:00.161 15201-15201/com.example.seve I/zygote64:     at android.view.ViewGroup androidx.appcompat.app.AppCompatDelegateImpl.createSubDecor() (AppCompatDelegateImpl.java:637)
2019-10-12 13:07:00.161 15201-15201/com.example.seve I/zygote64:     at void androidx.appcompat.app.AppCompatDelegateImpl.ensureSubDecor() (AppCompatDelegateImpl.java:518)
2019-10-12 13:07:00.161 15201-15201/com.example.seve I/zygote64:     at void androidx.appcompat.app.AppCompatDelegateImpl.setContentView(int) (AppCompatDelegateImpl.java:466)
2019-10-12 13:07:00.161 15201-15201/com.example.seve I/zygote64:     at void androidx.appcompat.app.AppCompatActivity.setContentView(int) (AppCompatActivity.java:140)
2019-10-12 13:07:00.161 15201-15201/com.example.seve I/zygote64:     at void com.example.seve.MainActivity.onCreate(android.os.Bundle) (MainActivity.java:19)
2019-10-12 13:07:00.161 15201-15201/com.example.seve I/zygote64:     at void android.app.Activity.performCreate(android.os.Bundle, android.os.PersistableBundle) (Activity.java:7088)
2019-10-12 13:07:00.161 15201-15201/com.example.seve I/zygote64:     at void android.app.Activity.performCreate(android.os.Bundle) (Activity.java:7079)
2019-10-12 13:07:00.161 15201-15201/com.example.seve I/zygote64:     at void android.app.Instrumentation.callActivityOnCreate(android.app.Activity, android.os.Bundle) (Instrumentation.java:1215)
2019-10-12 13:07:00.161 15201-15201/com.example.seve I/zygote64:     at android.app.Activity android.app.ActivityThread.performLaunchActivity(android.app.ActivityThread$ActivityClientRecord, android.content.Intent) (ActivityThread.java:2770)
2019-10-12 13:07:00.161 15201-15201/com.example.seve I/zygote64:     at void android.app.ActivityThread.handleLaunchActivity(android.app.ActivityThread$ActivityClientRecord, android.content.Intent, java.lang.String) (ActivityThread.java:2895)
2019-10-12 13:07:00.161 15201-15201/com.example.seve I/zygote64:     at void android.app.ActivityThread.-wrap11(android.app.ActivityThread, android.app.ActivityThread$ActivityClientRecord, android.content.Intent, java.lang.String) (ActivityThread.java:-1)
2019-10-12 13:07:00.161 15201-15201/com.example.seve I/zygote64:     at void android.app.ActivityThread$H.handleMessage(android.os.Message) (ActivityThread.java:1616)
2019-10-12 13:07:00.161 15201-15201/com.example.seve I/zygote64:     at void android.os.Handler.dispatchMessage(android.os.Message) (Handler.java:106)
2019-10-12 13:07:00.161 15201-15201/com.example.seve I/zygote64:     at void android.os.Looper.loop() (Looper.java:176)
2019-10-12 13:07:00.161 15201-15201/com.example.seve I/zygote64:     at void android.app.ActivityThread.main(java.lang.String[]) (ActivityThread.java:6651)
2019-10-12 13:07:00.161 15201-15201/com.example.seve I/zygote64:     at java.lang.Object java.lang.reflect.Method.invoke(java.lang.Object, java.lang.Object[]) (Method.java:-2)
2019-10-12 13:07:00.161 15201-15201/com.example.seve I/zygote64:     at void com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run() (RuntimeInit.java:547)
2019-10-12 13:07:00.161 15201-15201/com.example.seve I/zygote64:     at void com.android.internal.os.ZygoteInit.main(java.lang.String[]) (ZygoteInit.java:824)

You will need to generate a Signed apk:

https://www.jetbrains.com/help/idea/generating-a-signed-apk-through-an-artifact.html

To deploy and run an Android application on a physical device, you need to sign the application digitally. With IntelliJ IDEA, you can have your Android Application Package (.apk file) signed with an existing release key on package extraction. IntelliJ IDEA also incorporates a release key generation tool that can be invoked during the packaging procedure. Generated keys are saved in a keystore binary file.

You can have as many keystore files and keys as you need and use either existing keys, or create new ones in existing keystores, or even create new keystores.

Apart from using the Generate Signed APK Wizard, you can configure the .apk file as an artifact by creating an Android application artifact definition. When IntelliJ IDEA builds the package in accordance with this definition, the package is signed automatically.

User has mentioned in comments that he's using IntelliJ IDEA so this answer would be different depending on your IDE. Xamarin, for example, will generate the -Signed.apk whether or not you have it signed with a keystore, but that may vary by IDE.