“Conversion to Dalvik format failed with error 1” on external JAR

Question

In my Android application in Eclipse I get the following error.

UNEXPECTED TOP-LEVEL EXCEPTION:
java.lang.IllegalArgumentException: already add

Answer 1

If you have ADT revision 12+, you should update your proguard from 4.4 -> 4.6 (as described here). Also, you should leave ...\bin\proguard.bat file in the orginal form.

Just download it from the web, and copy lib folder from downloaded package to the :

[Android SDK Installation Directory]\tools\proguard\lib