Hey!
First, thanks for the new release! I really enjoy working with 2D toolkit.
I've just upgraded to 2.3 and ran into some problems, can't open the sprite collection editor in unity 4.3 for mac OSX at all.
I've created a fresh project and the error persists
Invalid editor window tk2dSpriteCollectionEditorPopup
UnityEditor.GenericMenu:CatchMenu(Object, String[], Int32)
Anyone having that issue?
EDIT: Under the layout tab choose the Reset to Factory Settings and the window appeared. Probably some issue with my unity installation.