wopen: 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/wopen - from package: gworkspace.app

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

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