Unable to open SonicWall Web UI due to an issue with RC4 (ERR_SSL_VERSION_OR_CIPHER_MISMATCH or SSL_ERROR_NO_CYPHER_OVERLAP)
To access Web UI from the Mozilla Firefox browser as a workaround:
Open Firefox and type about:config and it will ask you accept the risk so accept it and proceed further.
Now it will display with certain options and type security.tls in the search option and again you will be displayed with 7 options and select the first option that is security.tls_insecure_fallback_hosts.
Double click on above option security.tls_insecure_fallback_hosts and enter the SonicWall IP (Lan Interface IP) and click OK.
After all the steps restart the browser of preference and try accessing the SonicWall GUI.