gdbus: 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/gdbus - from package: glib2

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

On Debian possible default full paths are:

/usr/bin/gdbus - from package: libglib2.0-bin

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

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