citygml2vrml: 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/citygml2vrml - from package: libcitygml0-bin

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

Error in other languages:
citygml2vrml: bevel nie gevind nie
citygml2vrml: comandă negăsită
citygml2vrml: comando não encontrado
citygml2vrml: commande introuvable
citygml2vrml: command not found
citygml2vrml: käsku ei ole
citygml2vrml: không tìm thấy lệnh
citygml2vrml: komanda nerasta
citygml2vrml: Kommando nicht gefunden.
citygml2vrml: kommandot finns inte
citygml2vrml: komut yok
citygml2vrml: nie znaleziono polecenia
citygml2vrml: níor aimsíodh an t-ordú
citygml2vrml: no se encontró la orden
citygml2vrml: no s'ha trobat l'ordre
citygml2vrml: opdracht niet gevonden
citygml2vrml: parancs nem található
citygml2vrml: perintah tidak ditemukan
citygml2vrml: príkaz nenájdený
citygml2vrml: příkaz nenalezen
citygml2vrml: команда не найдена
citygml2vrml: командата не е открита
citygml2vrml: 命令找不到
citygml2vrml: コマンドが見つかりません