This issue came right after fresh instal ofl all my project on the brand new iMac i7. The issue is, that all my FCP X libraries are displayed as simple paper icon with folded corner, like it does not know what program it was created with. When double click, they all open with FCPX, so these work. However when choosing to display icons larger in the Finder > View > Show View Options window these all are displayed correctly with 4 square like Library icon.
As there is no fix permission option, I simply ran out of ideas what could be the issue.
I know its cosmetic, but a bit confusing when working with number of Libraries.