ctmviewer: 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/ctmviewer - from package: openctm-tools

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

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