I always recommend clicking the arrow to the right and launching standalone - if the launch happens to crash, your editor wont crash with it (which tends to cause corruptions in the editor and why many people likely are having to reverify a lot more than they should). As for why that generic map is doing that, I don’t know but maybe its best to start a new generic map from scratch. All you need to do is create a new level, change its gamemodeoverride, change its map name override, and throw in a global process blueprint in the scene outliner.