installvst: 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/installvst - from package: mono-devel

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

On Debian possible default full paths are:

/usr/bin/installvst - from package: mono-devel

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

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