ltspfs_umount: 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 CentOS possible default full paths are:

/usr/sbin/ltspfs_umount - from package: ltspfsd

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/usr/sbin/ltspfs_umount - from package: ltspfsd-core

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

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