fsserve: 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/fsserve - from package: python-fs

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

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