Error launching first test application: Android Packaging Problem?

Question

Conversion to Dalvik format failed: Unable to execute dex: 
wrapper was not properly loaded first   
[project]       
Android Packaging Problem

I've never worked with Java or eclipse before, I'm following this introductory guide and all searches via google return no helpful results. I'm guessing the problem is I have built Android stuff with eclipse properly but I have no idea, I followed this guide to the letter and everything went as it explains it should.

Any ideas what caused this problem, or is it specific to the guide? If so I'll post on their help page.

I have tried doing project -> source -> clean up, but that didn't fix anything.

Edit:

I went to Project -> Android tools -> Dex bytecode and it reported:

DexDump: missing classex.dex for project. Please compile first.

So I guess that's my problem! Not sure how to solve though.

Answer 1

Go to Project -> Clean

It will rebuilt workspace and fix the errors if any.