FileMerger: 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/FileMerger - from package: topp

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

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