If you are publishing Merlin projects from a computer that has a dynamically generated IP address, this can cause problems for your users already having received the project URLs and use in the meanwhile obsolete IPs to access the projects.  This situation easily occurs, as the IP address of your router changes upon re-connecting to your internet provider.
In this case the actual project URLs will fall out of sync with the URL and IP address that Merlin has originally published. Fortunately, there is a solution readily at hand allowing you to create a static host name that can be used instead.