“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

None of the listed solutions worked for me.

Here's where I was having a problem:

I added the jSoup external JAR file to my project's path by first putting it in a source folder called "libs", and then right clicking on it, Build Path -> add to build path. This threw the Dalvik conversion error. It said I had "already included" a class from that JAR file. I looked around the project's directory and found that the place where it was "already included" was in fact the bin directory. I deleted the JAR file from the bin directory and refreshed the project in Eclipse and the error went away!