Bookmark menu is full

Your bookmark menu on the entry page is full. Before you add a new bookmark to the menu you have to erase one that already exists.

Erase bookmark manually
Choose an existing bookmark in the menu on the entry page and erase it by clicking on the garbage can. Go to the entry page.

Erase oldest bookmark and add the new
Erase the oldest bookmark in the menu and add the new one by clicking here.