Checking the link...
Opening this destroys it. Make sure you can save or use the secret now - it cannot be shown twice, and nobody can recover it for you.
Here it is. It is gone from the server now.
{{ plaintext }}
This link is missing its key.
The part after the # is what decrypts the secret, and it is not here. Some chat and mail systems trim it when they rewrite links. Ask the sender to share the link again - by a route that keeps it whole, or pasted as plain text - and to create a new secret if this one has since expired.
The secret could not be decrypted.
The link opened, but the key in it does not match. That usually means the link was altered in transit. The secret has now been used up, so ask the sender for a new one.
This link is not valid.
It may have been opened already, or it may have expired. Secrets are destroyed once read, so a link only works the number of times the sender chose. Ask them for a new one.