You might have to update Flash.  I had the same issue with Poser 8 in Windows 7.  After updating Flash, the library returned.  Unfortunately, IE11 is incompatible with Poser 8 and in Poser 9 it needs to have the latest update to work with IE11.

Now I'm stuck with Windows 8.1 and IE11 so Poser 8 won't work at all and Poser 9/10 are much slower.  I'd go back to Windows 7, but I had a slowness problem with Vue 2014 so it's a losing battle either way.

Poser 2, 3, 4, 5, 6, 7, 8, 9, 10, Pro 2014, 11, 11 Pro