signver: 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/signver - from package: nss-tools

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

On Debian possible default full paths are:

/usr/bin/signver - from package: libnss3-tools

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

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