Hi,
You trying this on your own scene or example scene - and not working?
Can you try this:
1. Make new unity project.
2. Import Playmaker
3. Import PUN 1.28.3 from
https://hutonggames.fogbugz.com/default.asp?W9284. Get attachment from this post and move him to:
Assets/Photon Unity Networking/PlayMaker - Demo folder
5. Open this scene:
Assets/Photon Unity Networking/PlayMaker/Demo/playmakerTestGame.unity
or
Assets/Photon Unity Networking/PlayMaker/Demo/Separated Scenes Demo/demo_lobby.unity
And see if they working.
If example scene working, then something else is wrong with your game logic.
Also be careful with PhotonNetworkSetIsMessageQueueRunning.