MP3TAG Does Not See My Directory Files

Can anyone help please? I have opened up the programme and tried to import some MP3 files but the folder shows up empty when I try to add files to the program. The files are MP3 because I converted them from flac files

Do you use "File > Change Directory" ?
This is a folder browse dialog that shows only folders, no files.

I have just tried it the way you suggested and it has worked. Many Thanks dano.