ltsp-localappsd: 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
/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/ltsp-localappsd - from package: ltsp-client-core

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