I had the same problem because I would like to reuse keystore created to securized Nifi UI and because of the usage dedicated to Nifi (TLS including client authentication), it can't be simply use to activate TLS. Symptom: java.net.BindException: Address already in use: bind Clue: If you search for the the first exception, in my case, it was "java.security.UnrecoverableKeyException: Cannot recover key" So I guess, the server can't get the key even if SSLContext starts correctly and, as the server starts anormally, Nifi tries to restart and then a Bind exception raises. I just regenerated a very classic jks store for server authentication usage using keytool -genkey ... and all went like a charm ... Hope that help Jean-Louis , I had the same problem because I would like to reuse keystore created to securized Nifi UI and because of the usage dedicated to Nifi (TLS including client authentication), it can't be simply use to activate TLS. Symptom: java.net.BindException: Address already in use: bind Clue: If you search for the the first exception, in my case, it was "java.security.UnrecoverableKeyException: Cannot recover key" So I guess, the server can't get the key even if SSLContext start correctly !! I just regenerated a very classic jks store for server authentication usage using keytool -genkey ... and all went like a charm ... Hope that help ... View more