freeplane: command not found

Have You tried accessing the binary with the full path?

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/freeplane - from package: freeplane

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