im-chooser: 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/im-chooser - from package: im-chooser

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

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