An error occurred while encrypting the event. This covers all
OlmError types.
The Matrix SDK was compiled without encryption support.
We have no OlmMachine. This should not happen unless we forget to set
things up by calling OlmMachine::activate().
We refused to decrypt the message because the sender's device is not verified, or more generally, the sender's identity did not match the trust requirement we were asked to provide.
Reason code for a to-device decryption failure