Customizing the layout may result in missing window that gone forever.

[ryogilakya]

It's not an easy issue but it could happen and there's no way to fix it beside restart the program.

Step to replicate the bug (Removing a window)

1. Move all window out of a frame into other frame, make it blank black frame.
2. Try to move other window back into that frame. There should be the rectangle dots to indicate where the window will goes.
3. Try place and replace it into the blank frame some more time, Some time there will be no rectangle dots indicator. If the window were drop at this moment, It's gone forever. Until the program were restart and the interface revert back to its initial places.

I have try this many time, It take effort but I can even make the program became full blank screen.
But this can be happen accidentally.

Missing 3D view

Video of me try to remove some of the window
https://user-images.githubusercontent.com/30751699/129976178-0ef059dc-cb29-4c1d-a249-7b0313bd609e.mp4