I have a custom GUI that I have been working on, however, I have found that OnSceneGUI isn't called unless I select one of the default layouts from Window -> Layout -> (like 2 x 3 or something). If I use any of my custom saved layouts, it seems that no handles get rendered or are usable. I know this isn't just a problem with my GUI though. I also can't get the New Poly Shape tool to work with pro builder unless I go through the same process of selecting a different layout. There aren't any errors that get printed. I only tracked this down to the issue I'm seeing because of this (probably related) thread. I am not sure if this is a beta issue though, or one of the experimental systems. Anyone else having this problem? I couldn't find any issues raised related to this. Edit: after further exploration, it isn't just Handles that aren't working. It's actually OnSceneGUI that isn't called.