combine_tessdata: 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/combine_tessdata - from package: tesseract-ocr

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

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