Can't unpublish article

Hi ,
I am trying to modify a home page using a copy of the template. I am able to remove or insert most modules or articles.

However, when I try to unpublish the article Joomla Theme (Screen shot enclosed) I can not load the website as it reports an error. Image also enclosed.

What am I doing wrong?
Thank you in advance

Hi there,
please make sure that your "home" menu item is NOT linked to a disabled or deleted article