Sites disappeared from Global Admin

[happydg]

Hello,

On some of my sites, All sites and niches disappeared from Global Admin - Sites with update 51. I don't know why.

[admin]

If you don't see it in global admin - sites - then somebody just deleted it.

[happydg]

In fact it's just on one of my site which all sites has disappeared in global admin. But i can find this site on other sites global admin. I haven't deleted anything. How can i add all sites in global admin to this site without adding them one per one?

[admin]

Copy it to that site from another one using GA.