Error Running App Default Activity Not Found Solusi

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May 04, 2025

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Error Running App: Default Activity Not Found – Solutions and Troubleshooting

Getting the dreaded "Error running app: Default activity not found" message in Android Studio can be frustrating. This error means your Android app can't find the activity to launch when it starts. Don't worry, though – this is a common problem with easily fixable solutions. This guide will walk you through the most common causes and provide effective troubleshooting steps.

Understanding the Error

The core issue is a misconfiguration within your AndroidManifest.xml file. This file acts as a blueprint for your app, defining its components, including activities, services, and permissions. The "default activity" is the starting point of your application; without it properly declared, Android has nothing to run.

Common Causes and Solutions

Here's a breakdown of the typical reasons for this error and how to resolve them:

1. Incorrect or Missing intent-filter:

• Problem: The intent-filter within your activity declaration in the AndroidManifest.xml file might be missing or incorrect. This filter tells the system which activity should be launched when the app starts.
• Solution: Ensure your main activity declaration includes a <intent-filter> with an ACTION_MAIN and CATEGORY_LAUNCHER element. Here's how it should look:

Replace .MainActivity with the actual name of your main activity class. Double-check the package name and activity name for accuracy. A single typo can cause this error.

2. Incorrect Activity Name:

• Problem: You might have misspelled the name of your activity in the AndroidManifest.xml file. Even a small mistake will prevent the system from finding it.
• Solution: Carefully review the activity name in your manifest file, ensuring it exactly matches the class name in your Java or Kotlin code.

3. Multiple Activities with intent-filter:

• Problem: You might have multiple activities with the intent-filter defined. Android becomes confused about which one to launch.
• Solution: Review your AndroidManifest.xml and ensure only one activity has the <intent-filter> with ACTION_MAIN and CATEGORY_LAUNCHER. Remove the filter from any other activities unless they are intended to be accessed differently (e.g., through deep links).

4. Clean and Rebuild Project:

• Problem: Sometimes, a simple build issue can lead to this error. The project's build system might have become corrupted.
• Solution: In Android Studio, go to Build > Clean Project followed by Build > Rebuild Project. This often resolves minor inconsistencies.

5. Invalidate Caches/Restart:

• Problem: Your IDE's cache might be interfering with the build process.
• Solution: In Android Studio, go to File > Invalidate Caches / Restart... and select "Invalidate and Restart." This forces Android Studio to refresh its cache and rebuild the project from scratch.

6. Check for Gradle Errors:

• Problem: Errors in your build.gradle files can prevent the project from building correctly.
• Solution: Look for any errors or warnings in the Gradle console (usually at the bottom of Android Studio). Address these issues before attempting to run your app again.

7. Debugging the Manifest:

• Problem: Sometimes more complex issues within your AndroidManifest.xml cause this error.
• Solution: Carefully examine all aspects of your manifest, ensuring all elements are properly formatted and nested correctly. Look for any syntax errors. A second pair of eyes might be helpful here.

By systematically checking these points, you'll be able to identify and fix the "Error running app: Default activity not found" and get your Android application running smoothly. Remember to save your changes in AndroidManifest.xml after making any modifications. Always prioritize clean code and careful attention to detail when working with your app's configuration files.