“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

I had the same problem and none of these solutions worked. Finally, I saw in the console that the error was due to duplicated class (one in the existing project, one in the added jar file) :

java.lang.IllegalArgumentException: already added: package/MyClassclass;
[2011-01-19 14:54:05 - ...]: Dx1 error; aborting
[2011-01-19 14:54:05 - ...] Conversion to Dalvik format failed with error 1

So check if you are adding jar with duplicated classes in your project. If yes, try removing one of them.

It worked for me.