widgetserver: 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/widgetserver - from package: qtoctave

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

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