mate-thumbnail-font: 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 Debian possible default full paths are:

/usr/bin/mate-thumbnail-font - from package: mate-control-center

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

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