gsf-office-thumbnailer: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On CentOS possible default full paths are:

/usr/bin/gsf-office-thumbnailer - from package: libgsf-gnome

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/usr/bin/gsf-office-thumbnailer - from package: libgsf-bin

You may install the required package with command apt-get install {package}

Error in other languages:
gsf-office-thumbnailer: bevel nie gevind nie
gsf-office-thumbnailer: comandă negăsită
gsf-office-thumbnailer: comando não encontrado
gsf-office-thumbnailer: commande introuvable
gsf-office-thumbnailer: command not found
gsf-office-thumbnailer: käsku ei ole
gsf-office-thumbnailer: không tìm thấy lệnh
gsf-office-thumbnailer: komanda nerasta
gsf-office-thumbnailer: Kommando nicht gefunden.
gsf-office-thumbnailer: kommandot finns inte
gsf-office-thumbnailer: komut yok
gsf-office-thumbnailer: nie znaleziono polecenia
gsf-office-thumbnailer: níor aimsíodh an t-ordú
gsf-office-thumbnailer: no se encontró la orden
gsf-office-thumbnailer: no s'ha trobat l'ordre
gsf-office-thumbnailer: opdracht niet gevonden
gsf-office-thumbnailer: parancs nem található
gsf-office-thumbnailer: perintah tidak ditemukan
gsf-office-thumbnailer: príkaz nenájdený
gsf-office-thumbnailer: příkaz nenalezen
gsf-office-thumbnailer: команда не найдена
gsf-office-thumbnailer: командата не е открита
gsf-office-thumbnailer: 命令找不到
gsf-office-thumbnailer: コマンドが見つかりません