cef5conv: 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/cef5conv - from package: texlive-east-asian

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

On Debian possible default full paths are:

/usr/bin/cef5conv - from package: latex-cjk-chinese

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

Error in other languages:
cef5conv: bevel nie gevind nie
cef5conv: comandă negăsită
cef5conv: comando não encontrado
cef5conv: commande introuvable
cef5conv: command not found
cef5conv: käsku ei ole
cef5conv: không tìm thấy lệnh
cef5conv: komanda nerasta
cef5conv: Kommando nicht gefunden.
cef5conv: kommandot finns inte
cef5conv: komut yok
cef5conv: nie znaleziono polecenia
cef5conv: níor aimsíodh an t-ordú
cef5conv: no se encontró la orden
cef5conv: no s'ha trobat l'ordre
cef5conv: opdracht niet gevonden
cef5conv: parancs nem található
cef5conv: perintah tidak ditemukan
cef5conv: príkaz nenájdený
cef5conv: příkaz nenalezen
cef5conv: команда не найдена
cef5conv: командата не е открита
cef5conv: 命令找不到
cef5conv: コマンドが見つかりません