Sometimes when you try to use GMapTool to convert the finalized gmapsupp.img or gmapprom.img back to MapSource maps, the process might not be so smooth.
It might halt halfway with this error message: "Multiple products in img, creating TDB aborted, try option -f."
- ESRI Thailand StreetMap NT v10.1 (FID = 57)
- CN Hong Kong / Macau and Guangdong NT v7.61 (FID = 2082)
Now you can have the whole mapset splitting process complete and the installation file for MapSource created, despite some warning might come out along the process.
The bottomline is, you will be able to open and view the map in MapSource.