Battle of Windhelm Bug

[shim]

So I am just finishing the battle for windhelm quest with the imperials, and when Ulfric tells me to kill him, I do it, but it just says quest failed. Tullius and Rikke dont talk, and all of the people that are normally in the castle come in and just sit there. This also happens when i kill Galmar. I also tried letting tullius kill ulfric, but when i did he just walked up to him and stood there. They just looked at eachother. Does anyone know about this?

[Vita, Mortis, Careo]

I had a similar incident some time ago. Unfortunately, the only way I found to resolve the issue was to reload an earlier save.

[Trigger]

Civil War is covered by the Unoffical Skyrim Patch-do you have it