In order for transport playback and recording to work in the plug-in the the DAW must be streaming audio into the plug-in.

While this works automatically in most DAW's in some others you must input monitor the track which is sourcing the plug-in or start playback in the DAW for this to work. If the plug-in is not receiving audio and you press play in the plug-in transport you will see a message telling you to start playback in the host.