Clients and servers are never updated at exactly the same time - even when you try to update them at the same time. One or the other may get rolled back. Don’t assume that you can make a breaking change and it’ll be okay because the client and server are in sync. Don’t Re-use a Tag Number Never re-use a tag number. It messes up deserialization. Even if you think no one is using the field, don’t re-use a tag number.
