That's odd. If you connect to the server app with the client, and pause the server (the pause button in PerfStudio 2), the profiling buttons should become available after frame capturing completes. Be aware, this does take a few seconds.The pause button becomes available, when the connection button turns red.
I haven't had any issues with PerStudio 2 (except it crashing when using glMultiDraw....). I'm exclusively using it on my main development rig (R9 290).
P.S. If you have an NVidia machine available, you should also look at nSight that offers similar functionality.