This dreaded bug is happening in SSE too :( It basically kills the Civil War questline, typing setstage CW03 210 doesn't trigger the battle for Whiterun and skipping the whole battle by typing setstage CWSiegeObj 9000 doesn't help either since after that Tullius won't give the correct dialogue option to continue. So far I've done these with poor results: -finished the main quest -tried with mods disabled -tried reloading an earlier save -tried setting the faction rank to 4 -made sure my bounty was 0 -tried a new character (!) Only thing I can still think of trying is a new save without the unofficial patch and/or alternate start