“Conversion to Dalvik Format Failed with Error 1” on External JAR in Eclipse

"Conversion to Dalvik Format Failed with Error 1" on External JAR in Eclipse

22 May 2024 Stephan Petzl Leave a comment Tech-Help

Encountering the “Conversion to Dalvik format failed with error 1” error in your Android application can be frustrating. This error typically occurs when adding a specific external JAR file to your project, leading to conflicts or duplications. Here, we outline a step-by-step guide to resolving this issue effectively.

Understanding the Error

The error message generally looks like this:

  java.lang.IllegalArgumentException: already added: Lorg/xmlpull/v1/XmlPullParser;

This indicates that the Dalvik converter has encountered duplicate class definitions, often due to conflicting JAR files or package name conflicts.

Step-by-Step Solution

1. Clean Your Project

First, try the simplest solution:

  • Go to Project » Clean
  • Select your project and click OK

This action removes all compiled files and forces Eclipse to rebuild the project from scratch.

2. Check for Duplicate JAR Files

Ensure that you do not have duplicate JAR files in your project:

  • Go to Project » Properties » Java Build Path » Libraries
  • Remove all entries except the “Android X.Y” (e.g., Android 1.5)
  • Click OK

If you have JAR files located inside your project folders and added as Java Path Libraries, they might not show up under the Package Explorer but can cause duplication issues.

3. Resolve Package Name Conflicts

If you have a package with the same name in multiple locations, it can cause this error. Ensure that no two JAR files or library projects contain the same package and class names.

4. Avoid Manual Classpath Edits

Check if you have manually edited the classpath file. Sometimes, adding the android.jar path manually can cause issues. Remove any manual additions to the classpath file and regenerate your JavaDoc if needed.

5. Update ProGuard

If you are using ProGuard, ensure it is updated to the latest version:

  • Download the latest ProGuard version
  • Replace the lib folder in your Android SDK’s ProGuard directory

Additional Tips

  • Disable Build Automatically while exporting your application, and don’t forget to turn it back on afterward.
  • Ensure no unnecessary JAR files are included in your build path.
  • Perform a Lint Check via Android Tools » Run Lint: Check for Common Errors to identify issues.


By following these steps, you should be able to resolve the “Conversion to Dalvik format failed with error 1” error and successfully build your Android project in Eclipse. For more detailed guides on Android development issues, you can refer to our other blog articles:

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