On a modern 4k display, the main window is too tiny to display even all of the title text. I found a default of 300x300 works a lot better. I changed it at line 646 in GUI_Main.lua.
(I don't see value in changing the default position, since everyone will have their UI set up differently and will drag it to unique places. But a bigger default size also makes it easier to grab the title bar to drag it.)