I found a bug in Quickr 8.5.1 FP27.
If you create a page/upload/etc and you select the option "send notification", you should be able to select from the placemembers list so that they get notified per mail about the new document.
But the memberlist is empty and you could not select members for notification. This is reproduceable in different VMs/customer installations.
The "send link" option is not affected and works fine.
If you need this function stay on FP26 or wait for new FP.