nspluginscan: 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/nspluginscan - from package: kdebase

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

On Debian possible default full paths are:

/usr/bin/nspluginscan - from package: konqueror-nsplugins

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

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