I am unable to establish connection between Mule4 (Any point Studio) to Salesforce FSL. Even i entered correct username, password & security token throwing error message like org.mule.runtime.api.connection.ConnectionException: Invalid username, password,

Thanks, gopal for your response. I already tested with portal page login and able to login successfully.

As you suggested, i need to look into firewall or proxy settings, will check and get back to you.