Then, if it's and Web XPanel, and you are using 2 series processor or DMPS3-4K-150, You need to put Core 3 XPanel Web Configuration Module v1.1 (from Crestron Modules Database) anywhere in the Simpl program, or it will not connect. You have to have a XPanel defined in your Simpl program, and have it at the same IP ID as your UI project. If you want to upload XPanel to the processor, and use processors web server to host it, make and upload XPanel 2.0 (Web) Smart Graphics.