wxBTreeDemo: 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/wxBTreeDemo - from package: stx-btree-demo

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

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