sediffx: 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 CentOS possible default full paths are:

/usr/bin/sediffx - from package: setools-gui

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/usr/bin/sediffx - from package: setools-gui

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

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