Stuck with the "binary operator expected" message

Stuck with the "binary operator expected" message when I run this command :

for variable in "ebooks" "movies" "games" "softwares" "music" "series" "tvreplay"
do
    if [ -d /in/recep/downloader_ftp*/${variable} ]
    then
        mv /in/recep/downloader_ftp*/${variable}/* /in/arch/${variable}/ 
    else
        echo "no files type ${variable}"
    fi
done

I know this is because the command find 2 directories starting with the pattern "downloader_ftp*" in the recep directory, but I can't figure good way to do it.