@bozulurmu: If you remove the schema.org markup for the unlinked breadcrumb templates, the error will go away. It doesn’t look like the site you linked to is not using the default breadcrumb templates, you’ll need to remove references to itemtype, itemscope, temprop, and the meta tag from your unlinked breadcrumb templates. Since you do not have the breadcrumb trail on your home page, this should resolve the issue for you.
@asc1212: From what you posted before, you need to update your unlinked breadcrumb templates so that they do not contain schema.org markup (e.g. use <span class="%type%">%htitle%</span>
), this has been the answer for quite a while, and is what the default settings are now (previously the schema.org markup was erroneously included in the unlinked breadcrumb templates).
@rom174: I’ve seen a few ways that people have suggested handling adding the URL to unlinked breadcrumbs, I’m not sure any method is standard per say. However, I do know that currently, Breadcrumb NavXT usually will not have the URL available for unlinked breadcrumbs. This is likely to change in future versions to allow more flexibility (see https://github.com/mtekk/Breadcrumb-NavXT/issues/226).