Android Error – Error in Imported Libraries

When you get the following error in a project:

Conversion to Dalvik format failed with error 1

Solution

Right-click the project and choose "Properties".

Go to the Android tab and, at the very bottom, remove all the libraries that are listed. Apply the changes and then add back the ones you need.

Close the window and check that you no longer get any errors.

If you still get the same error, go back to the previous tab and remove the libraries again. Leave them removed this time.

Then, in the same window, go to “Java Build Path” and open the Libraries tab.

You need to remove all the library references except the one called “Android X.Y” (where X.Y is the version of the operating system; in the example it is 2.1).

Close the window and look at your class to check that no red crosses appear. If there are none, it will work now.

If there are red crosses, take note of where they are, since those will be libraries that haven’t been removed, and go back to the previous window.

Now go to the Source tab. There, delete everything except the folders ending in “/gen” and “/src”.

Close the window and find the ones you noticed earlier that had the red cross and now don’t. Delete them manually. Everything should work now.