I get this issue my self from time to time. For me it helps to run the game in windowed mode, and while the game is booting up, as soon as the SQUAD logo disappears and the 'Loading' screen starts I click and drag the screen around (the window turns black while dragging it around). I usually drag it around for a couple of seconds, release to see that it starts loading, then drags it around a little more. When it reaches around 20-30% loaded, is stop dragging it. Works 99% it of the time.