"Empty .DSK files" how I can write them in a real floppy disk??

Those dsk files are a sector-by-sector copy of the original disks. So a MSX programmer can decide to ignore the regular MS(X)-DOS filesystem structure and access the disks directly bypassing the more common directory and filenames structure. So your PC Disk-manager correctly concludes that it can not read files and/or directories on such an image since they aren't there. But that also means that you can not 'fix' those images, they are working as intended. You will need an other program that can copy those dsk files sector per sector to a regular disk.

On Linux you can do this on the command line with the command 'cp image.dsk /dev/fd0' where you replace 'image.dsk' with the filename of the dsk you want to copy and /dev/fd0 needs to be the correct device name of your floppy. Unfortunately I can't help you with a Windows alternative, probably somebody else here can.

Also keep in mind that MSX uses Double Density floppies(720KB) while PC uses High Density(1.4MB) floppies. Some PC floppy drives have trouble handling DD floppies. So even with the correct software the hardware might not be able to correctly write the disk.

Well, there's the Floppy Drive Image tool by Alank2. It's a command line tool that supports single sided disks as well. Scroll down the page for version 1.01.