gnc-fq-check: 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/gnc-fq-check - from package: gnucash

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

On Debian possible default full paths are:

/usr/bin/gnc-fq-check - from package: gnucash

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

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