Android – Unable to execute dex: Multiple dex files define Lcom/theapp/R$array;

adtandroidandroid-sdk-toolsdexeclipse

Since updating to ADT 14 I can no longer build my project. It was building fine prior to updating.

The error:

[2011-10-23 16:23:29 - Dex Loader] Unable to execute dex: Multiple dex files define Lcom/myapp/R$array;
[2011-10-23 16:23:29 - myProj] Conversion to Dalvik format failed: Unable to execute dex: Multiple dex files define Lcom/myapp/R$array;

Similar issues have been reported and I have tried the suggestions there including

  • Restarting Eclipse.
  • Cleaning the project and rebuild – Disable "Project->Build Automatically" option, then "Clean" and "Build" project, then try to run. reset "Build Automatically" option to On
  • Re-installing the Android Developer Tools
  • Re-installing Eclipse (updated to the latest version 3.7.1)
  • Created a new project importing from the file system
  • Created a new project from subversion.

Best Solution

I had the same problem, quite weird because it was happening only when using Eclipse (but it was OK with Ant). This is how I fixed it:

  • Right click on the Project Name
  • Select Build Path -> Configure Build Path
  • In Java Build Path, go to the tab Order and Export

  • Uncheck your .jar library

Only sometimes: In Order and Export tab I did not have any jar library there, so I have unchecked Android Private Libraries item. Now my project is running.