I couldn't replicate the bug as previously described. However I was able to replicate it by pausing the game with ESC, pressing F2, then F1, then F2 again. I have a Google Drive folder with a snipped KSP.log and some images. Fortunately for this bug, KSPClock doesn't hide with F2 at all so it shows the time the images were dumped into screenshots which should match the log. The Google Drive folder is located here. Now it is bedtime for me. No more KSP till later. Edit: I was able to bring the Fusebox window back by turning off the Fusebox window with the toolbar button while the game was paused with ESC, then turning the Fusebox window on with the toolbar button after the game was unpaused.