unipagecount: 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 Debian possible default full paths are:

/usr/bin/unipagecount - from package: unifont-bin

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

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