grid-cert-diagnostics: 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/grid-cert-diagnostics - from package: globus-proxy-utils

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

On Debian possible default full paths are:

/usr/bin/grid-cert-diagnostics - from package: globus-proxy-utils

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

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