I guess I have the best chance for a solution in the official bethesda forum, so excuse me for my bad english, I'm from Germany...but my problems seems to be very rare and i didn't find the solution elsewhere.
The problem is simple. After obtaining Auriel's Bow, the next quest won't start. I sided with the Volkihar Vampires. Serana doesn't have new dialogue, except for creating bloodcursed arrows. I tried every dialogue option of Gelebor but this don't change anything. I found a discussion about this bug on uesp wiki. It seems I can't post links in this forum, so just search "skyrim talk kindred judgment" via Google, it is the first page.
I tried almost very idea mentioned there. I tried the following console commands:
setstage DLC1VQ08 10 or 20
---------------------------------------
completequest DLC1VQ08
resetquest DLC1VQ08
setstage DLC1VQ08 10
There is no output and no quest update.
I tried this suggestion as well:
"After having this bug for weeks, I was able to fix it with a combination of the creation kit and setstage. Apparently its some dialogue condition for Serena that is preventing the quest from starting. So I enabled this quest in creation kit to 'Start Game Enabled'. This made it so after getting the bow, I would start Kindred Judgement. Serena still wouldn't have the dialogue option at this point. But I was able to setstage DLC1VQ08 20 to skip that part and move things ahead so I could showdown with Harkon. I have the .esp file if people want it."
I created a esp like that. I enabled "Start Game Enabled", but it doesn't help me either.
I'm not sure whether or not old savegames have the same problem. At first, I thought the setstage command would work with savegames before starting the dawnguard questline and sucessfully start the quest. But I retried it and now the console command won't start the quest even in completely new savegames. Maybe I used a wrong ID at first...
By using the command "setstage DLC1VQ08 20", I just get the output (with savegames before starting the dawnguard questline)
GetGlobalValue >> 0.0
GetGlobalValue >> 0.0
That is everything I tried so far. Of course I also deactivated every Plugin for all my test, but that doesn't help. Last idea would be complete reinstalltion, but I would like to avoid that, because I can't know if that will fix the problem and I have very slow internet (250 kb/s), so it would take quite a while.
But despite the deactivation of my plugins, I post here my compelte plugin list:
GameMode=Skyrim
Skyrim.esm=1
Update.esm=1
Dawnguard.esm=1
Dragonborn.esm=1
HearthFires.esm=1
ClimatesOfTamriel.esm=1
Falskaar.esm=1
Masters of Death.esp=1
ReProccer.esp=1
SkyRe_Main.esp=1
SkyRe_Races.esp=1
SkyRe_StandingStones.esp=1
SkyRe_Combat.esp=1
SkyRe_EnemyAI.esp=1
SkyRe_EnemyScaling.esp=1
SkyRe_EncounterZones.esp=1
SkyRe_Survivalism.esp=1
Chesko_Frostfall.esp=1
SkyUI.esp=1
Civil War Overhaul.esp=1
ClimatesOfTamriel-Dungeons-Hazardous.esp=1
ClimatesOfTamriel-Interiors-Cold.esp=1
ClimatesOfTamriel-Nights-Level-3.esp=1
Brevi_MoonlightTales.esp=1
DeadlyDragons.esp=1
DeadlyMonsters.esp=0
Better Vampires.esp=1
DeadlyDragonsSpells.esp=1
WATER.esp=1
WATER Plants.esp=1
WATER DB Waves.esp=1
DragonCombatOverhaulDragonborn.esp=1
SoS - Civilization.esp=1
SoS - The Dungeons.esp=1
SoS - The Wilds.esp=1
DeadlyDragonsArmory.esp=1
Predator Vision.esp=1
Alternate Start - Live Another Life.esp=1
Convenient Horses.esp=1
MidasSkyrim.esp=1
throneroom.esp=1
Vampirelordroyal.esp=1
BVandRB_Formlist.esp=1
Midas Magic Expanded.esp=0
I tried the unofficial Dawnguard Patch, but that doesn't work.
And I have an even bigger problem now. I tried so solve problem with an esp file I created, but the esp file broke the quest "Touching the Sky", I can't obtain Auriel's Bow and the quest won't complete correctly. I deactivated the esp file and deleted it, but the quest is still broken. Why does a simple esp file break my game forever without saving the game? New games are broken, too. I can't start the quest "Touching the Sky" with the console. I consider to reinstall the whole game, because I have two broken quests now, but I thought give it a last try in this forum...