This is a regression—in Electron 0.35.1, draggable regions of the window stop working when the developer tools are opened. This means that the window effectively can't be moved while the developer tools are open. It doesn't matter if the developer tools are docked or in a separate window.

I think this might be a side effect of an intentional change? In previous versions, you couldn't use the "Inspect Element" feature to click and select part of the DOM that was in a draggable region (since it was still draggable.) That now works (I can hover over and click on my title bar), but I can't move the window.

Here's a sample app to reproduce. Open the app, enable "top toolbar" and then open the developer tools:

https://dl.dropboxusercontent.com/u/4803975/frameless-window.zip