When I do /backpack nothing happens, same if I bind it to a key as far as I can tell it's only me on the server everyone else is working. Is there an admin command to reset my backpack ( with or without loosing everything in it? )

 make sure you have been granted permission. if you grant yourself permission again and you already have it it will show in chat, as for binding a key the docs say use b so thats probably the best bet

That didn't fix it for me