jbig2dec: 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/jbig2dec - from package: jbig2dec

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

On Debian possible default full paths are:

/usr/bin/jbig2dec - from package: jbig2dec

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

Error in other languages:
jbig2dec: bevel nie gevind nie
jbig2dec: comandă negăsită
jbig2dec: comando não encontrado
jbig2dec: commande introuvable
jbig2dec: command not found
jbig2dec: käsku ei ole
jbig2dec: không tìm thấy lệnh
jbig2dec: komanda nerasta
jbig2dec: Kommando nicht gefunden.
jbig2dec: kommandot finns inte
jbig2dec: komut yok
jbig2dec: nie znaleziono polecenia
jbig2dec: níor aimsíodh an t-ordú
jbig2dec: no se encontró la orden
jbig2dec: no s'ha trobat l'ordre
jbig2dec: opdracht niet gevonden
jbig2dec: parancs nem található
jbig2dec: perintah tidak ditemukan
jbig2dec: príkaz nenájdený
jbig2dec: příkaz nenalezen
jbig2dec: команда не найдена
jbig2dec: командата не е открита
jbig2dec: 命令找不到
jbig2dec: コマンドが見つかりません