imediff2: 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/imediff2 - from package: imediff2

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

Error in other languages:
imediff2: bevel nie gevind nie
imediff2: comandă negăsită
imediff2: comando não encontrado
imediff2: commande introuvable
imediff2: command not found
imediff2: käsku ei ole
imediff2: không tìm thấy lệnh
imediff2: komanda nerasta
imediff2: Kommando nicht gefunden.
imediff2: kommandot finns inte
imediff2: komut yok
imediff2: nie znaleziono polecenia
imediff2: níor aimsíodh an t-ordú
imediff2: no se encontró la orden
imediff2: no s'ha trobat l'ordre
imediff2: opdracht niet gevonden
imediff2: parancs nem található
imediff2: perintah tidak ditemukan
imediff2: príkaz nenájdený
imediff2: příkaz nenalezen
imediff2: команда не найдена
imediff2: командата не е открита
imediff2: 命令找不到
imediff2: コマンドが見つかりません