dirmngr-client: 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/dirmngr-client - from package: dirmngr

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

On Debian possible default full paths are:

/usr/bin/dirmngr-client - from package: dirmngr

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

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