show-tiling: 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/show-tiling - from package: mummer

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

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