Late last night, I achieved a breakthrough. The file name in the original data base was different from what I had originally reported. After repeating the creation process, using the correct database file name, all is working properly.
My original database was created, using MusiCHI software. MusiCHI was developed in Europe and the developer had used a word which is probably French as the name for that field, but had translated the word into "Period or Style" for the display name. I finally realized what was going on and used the original word in the MusicBee creation process.
Success!
Sorry for the flurry of emails. But, as always, thanks for the help.
Art