split_stl: 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/bin/split_stl - from package: slic3r

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