When creating a new application in MDT, you get the following message:
Application name “application name” is already used.
This error occurs when trying to create a new app with a name that was used and the app was deleted.
1. Open the Applications.xml 1 file (with notepad++) located in X:\DeploymentShare\Control
2. Delete the lines corresponding to application 1 and save the file.
3. It is now possible to use the name.