Hope this isn't too late, but there are a couple fixes. This is happening because your project is configured (Properties > Flex Compiler > ) to use a specific version of the Flash Player or the minimum version for the SDK (126.96.36.199) , but your Flash Builder installation is pointing at a different version of the Flash Player debugger (11.4.402.265).
So you can do two things:
Download the required version of the Flash Player debugger and configure Flash Builder to use that executable when debugging
1. Click on the "Adobe Flash Player downloads" link in the dialog.
2. Click on the Download the Windows Flash Player 14 Project, which is the FlashPlayer executable that runs in Windows.
3. Copy the file to a new folder in the Flash Builder installation next to the existing 11.4 Flash Player (see your screenshot it is c:\Program Files\Adobe\Adobe Flash Builder 4.7\player\win\11.4)
4. Back in Flash Builder
5. Open Windows > Preferences
6. Navigate to Flash Builder > Debug
7. In the Standalone Flash Player(debug version) field click the ellipsis button to launch a file dialog
8. Navigate to the Flash Player executable you downloaded and copied into the Flash Builder installation above
9. Click OK to save the settings
Update the project properties to point to the same specific version that Flash Builder is using (11.4.402.265)
1. Right click your project
2. Select Properties from the context menu
3. Navigate to the Flex Compiler panel
4. Change the Adobe Flash Player Options field to 11.4.0
5. Click OK to apply the changes