disp_profile: 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/lib/mrtrix/bin/disp_profile - from package: mrtrix

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

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