.app file appears in red (missing) in new projects with Xcode 4

Try Building and Running on a device, I've noticed the same red text problem, but selected my iPhone and the red text has disappeared.

I have solved the problem with the following process:

1. Select projectname -> Click project -> Build Setting -> Search "Per-configuration Build Products Path"

2. Remove the extra string from there.

3. Finally confirm you have to add $(BUILD_DIR)/$(CONFIGURATION)