I also had this problem, and its 'cause you need to indicate whether
the references will be copied to the output directory, to do this fallow
the next steps:
1. Select any of the reference you are using from on Solution Explorer
2. Go to "References"
3. Do right click on any of the DevExpress References your are using.
4. Choose "Properties" and on "Copy Local" property, set a "True" value.
5. Build and Run your app! again ;)