ackinfo.cgi: command not found

Have You tried accessing the binary with the full path?

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH

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 Debian possible default full paths are:

/usr/lib/xymon/server/bin/ackinfo.cgi - from package: xymon

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