there are some strange issues here with FMS13 - but usually, restarting the server-machine helps..
- FMS runs fine for weeks, but sudently the admin-page is no longer available or shows wrong data when openen from another machine
- same may happen when the admin-page is openend from the server-machine
See http://forums.filemaker.com/posts/2b47dd5711?commentId=284438#284438. I was running a test server on my laptop already with that license. Once I quit that and restarted FileMaker Server the databases show normal.