imsettings-restart: 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/imsettings-restart - from package: imsettings

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

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