Q:

error when exporting.  apk

killed 3 hours for this error.  Search the forums did not give (anything you want)
compiles on the emulator well.  but for export if the problem
com.android.ide.eclipse.adt.internal.build. DexException: Conversion to Dalvik format failed with error 1
    at com.android.ide.eclipse.adt.internal.build. BuildHelper.executeDx(BuildHelper.java:663)
    at com.android.ide.eclipse.adt.internal.project. ExportHelper.exportReleaseApk(ExportHelper.java:204)
    at com.android.ide.eclipse.adt.internal.project. ExportHelper$2.run(ExportHelper.java:301)
    at org.eclipse.core.internal.jobs. Worker.run(Worker.java:54)

help those who faced

A:

It happened to me once while using proguard and I was able to solve using -forceprocessing in proguard.cfg

A:

I needed to update proguard, and the issue is resolved

