“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

You can solve this issue easily (with Eclipse Android Developer Tools, Build: v22.0.1-685705) by turn off menu > "Project" > "Build Automatically" while exporting (un)signed Android application. After that, don't forget to turn it on again.