seapplet: 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/seapplet - from package: setroubleshoot

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

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