That error is related to the cipher choosen by the server for the SSL handshake. It is not secure and probably disabled in our JRE.
What you can try is to edit the <install_dir>\controller.properties and comment that option: https.ciphers.whitelist putting "#" sign at the beginning. Restart your NeoLoad and try again.
Another way to fix that is to check the cipher used when you manually browse to your application and use it in that "https.ciphers.whitelist" list by even removing all the others or by putting yours at the beginning of the list.
A quick Google suggests it's a JRE bug, what version of Neoload are you using? maybe upgrade Neoload or update the JRE? updating the JRE Neoload uses may mean your configuration of Neoload is unsupported