Hi

In my current project, Playmaker throws the following errors after I press play:
NullReferenceException: Object reference not set to an instance of an object
HutongGames.PlayMakerEditor.FsmEditor.OnDisable () (at c:/Users/Alex/Documents/Unity/Playmaker/Projects/Playmaker.source.unity/Assets/PlayMaker/Editor/Classes/FsmEditor.cs:1052)
HutongGames.PlayMakerEditor.FsmEditorWindow.OnDisable () (at Assets/PlayMaker/Editor/FsmEditorWindow.cs:384)
The errors don't interrupt gameplay, but its annoying to see the red messages everytime I start the game. Even if I change the scene, the errors appear which is why I assume it has something to do with the playmaker installation.
Did anybody encounter this issue before? Is there a solution? Should I just reinstall Playmaker (how do I do this without corrupting some files?).