Android: Unable to Instantiate Activity/Classnotfoundexception

Unable to instantiate activity Component Info Class Not found exception Android

As Discussion in chat i found that, Your manual way of generating APK
is not generating the correct APK, so i am Suggesting these way to
generating APK for Manual Install:

For Debug Build

• Delete you build folder inside the App folder.
• Goto Build>Build APk. it will generate .apk file in your
  app>build>output>apk directory.
• COPY it your device and install manually.

For Release Build

• Delete you build folder inside the App folder.
• Goto Build>Generate Signed APk and provide recomended Details, make sure your Build type : release and have checked both signature version v1(jar signature) and v2(full apk signature) . it will generate .apk file in your
  app>build>output>apk directory.
• COPY it your device and install manually.

java.lang.RuntimeException: Unable to instantiate activity ComponentInfo

It is a problem of your Intent.

Please add your Activity in your AndroidManifest.xml.

When you want to make a new activity, you should register it in your AndroidManifest.xml.

java.lang.RuntimeException: Unable to instantiate activity ComponentInfo/ ClassNotFoundException

When upgrading, the 'Order and Export' of the new 'Android Private Libraries' is not always checked. And the android-support-v4.jar is now in this 'Android Private Libraries' section.

To fix this, go to 'Order and Export' and check 'Android Private Libraries'. Then refresh/clean/rebuild.

After you done this 'fix' for a library project, you may need to just close and re-open any depending project, because they may not see this 'fix' immediately.

Android - Unable to instantiate activity

The problem fixed itself after some updates to android studio!

Beginner Android java.lang.RuntimeException: Unable to instantiate activity

What is your logcat throws

Caused by: java.lang.ClassNotFoundException: Didn't find class
"com.example.imran.justjava.MainActivity"

ClassNotFoundException : ClassNotFoundException occurs when class loader could not find the required class in class path . So , basically you should check your class path and add the class in the classpath.

I guess your activity in manifest is not correct.

Post your manifest.xml .

Have a look here
https://developer.android.com/intl/es/samples/BasicContactables/AndroidManifest.html

Example

<activity
      android:name=".MainActivity"
       >
   
      <intent-filter>
         <action android:name="android.intent.action.MAIN" />
         <category android:name="android.intent.category.LAUNCHER"/>
      </intent-filter>
   
   </activity>

java.lang.RuntimeException: Unable to instantiate activity ComponentInfo for Kotlin MainActivity

Try to apply kotlin in build.gradle file at starting

apply plugin: 'com.android.application'
apply plugin: 'kotlin-android-extensions'
apply plugin: 'kotlin-android'
apply plugin: 'kotlin-kapt'

android {
compileSdkVersion 28

Android - Unable to instantiate activity - Class not found exception after upgrading to ADT 22

Might be a duplicate of this.

Try going to Project -> Properties -> Java Build Path -> Order & Export and ensure
Android Private Libraries are checked for your project and for all other library projects you are using. Clean all projects
afterwards and see what happens.

---

Related Topics