I'm running CentOS 7.4 with PHP 5.4.16 and Server version: 5.6.38 MySQL Community Server (GPL).
I put a fresh installation of Joomla 3.8.1 and I can't add a menu, the menu types it displays in the pop-up dialogue are all blank. When I go to the media to view the graphic files, none of them are shown. Very odd problem. If I right-click and open the media files list in another window, I can then see them. I've tried this on different web browsers and different workstations Mac and Windows, same problem.
I'm just guessing, could this be some sort of ACL thing where it isn't permitting admin to have access? Sounds odd, but I don't know if that could be a problem.