pamusb-agent: 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/pamusb-agent - from package: pamusb-common

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

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