Did you made any changes to theme files? Or installed any new plugin lately? Make sure you have set up the home page in General Options and in Settings > Reading. You should assign an existing slider to homepage, or create a slider named “home”.
If the issue persists, send us your wp credentials in a private reply. So we can give a closer look.
The home slider was calling a slider that did not exist. I created it, with the required slug and now it’s ok. You had chosen the light version of style 1, for header. I changed that too, in Page Options & Styles (screenshot). It all look ok now.
