This Network Can't Be Opened
What happened
This network was created before Council changed how it derives a network's encryption root. The value stored for it was produced by the older method, the current app can only produce the newer one, and the two do not match. The server rejects every unlock attempt for this network, no matter what is entered.
Your key is not the problem. If you have the correct key, it is still correct. It simply has nothing left to unlock on this particular network. Ask the network owner to create a new one.
Common causes
- The network was created before the encryption-format change and was never re-created afterward
How to fix
- Do not keep entering the key. No number of attempts can succeed here
- If this network still matters to you, the owner needs to create a new one and re-invite its members
- Contact support if you believe this network should still be openable, and include the network name
Why the messages cannot be recovered
Messages and files in this network cannot be recovered. Council never held a key that could read them, so there is no copy to restore from. That is the same property that keeps your content private, and it applies here too. Your account, your other networks, and your key itself are unaffected, and networks created after the format change are not affected by this.