removable_storage_watcher: 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/lib/plainbox-providers-1/checkbox/bin/removable_storage_watcher - from package: plainbox-provider-checkbox

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

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