NEMS Linux uses SSL (aka https) connections to secure your connection and the data you transmit and receive to and from your NEMS server. This is accomplished using what is called a self-signed certificate. By nature, self-signed certificates are considered “untrusted” by your browser because, simply put, anyone can make them. It does not mean your connection is not encrypted or secure, but rather it means your browser cannot determine who created the certificate, and therefore they cannot verify your security. If you visited a web site, say google.com and received a warning that your connection is not secure, you should immediately stop what you're doing and not proceed. However, in the case of NEMS Linux, which is a local server on your network (not a “dot com” on the web), you can safely trust the self-signed certificates and add an exception to your browser.