Zenity Glib warning? What does it mean? Is it important?

(zenity:1947): GLib-WARNING **: /build/buildd/glib2.0-2.40.2/./glib/giounix.c:410
Error while getting flags for FD: Bad file descriptor (9)

Here is the code:
myfalse="FALSE"

FileDir=`let Count=1
   while [ $Count -lt ${#line[@]} ]; do
   echo $myfalse
   echo "${DisplayLine[$Count]}"
 Count=$((Count+1))
done | zenity --list --radiolist --timeout 60 --width 500 --height 400 \
     --text "Select Topic on which you want to answer questions" \
     --column "Topic" --column "Select one of these" `

The code works. The directories are found and displayed and if the user selects one, FileDir does contain the selected directory name. However, the above message is sent to standard error.