exrenvmap: 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/exrenvmap - from package: OpenEXR

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

On Debian possible default full paths are:

/usr/bin/exrenvmap - from package: OpenEXR

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

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