Depending on whether you have a disk or download file install, the installation may or may not have installed the library files.
Based on what you are seeing for the library sets options, your preferences are not set for the correct library location. But that could be weird for many reasons.
Edit -> Preferences -> Media. Confirm/change the location to the Encore appolications folder and the "Library" folder within that.
Are you certain that you were running Encore 5.0 under OSX 10.9? Or it exhibited problems and you uninstalled/reinstalled trying to get it to work?
I cannot get anythimg to "play" in the timeline, not by just pushing play using the monitor, or using the simulator.
What "play" button are you referring to? There is no "play" button in the Encore preview.