OK, somewhere in your xLights you should have a file called 'xlights_networks.xml'. Mine is in my xlights/sequences folder. Go into your system, and find where this file is and make a note of it.
Once you find it, go back to xSchedule. On the 'file' menu, there is a option to select your 'Show Folder'. Set this to the same folder where the xlights_networks.xml file is.
Then save everything, and give it a try...