tsorts: 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/tsorts - from package: opencaster

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

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