Bug quest : "could not resolve any root: QuestDescription"

[Dulhby]

Hello everyone, I have a problem with mylast two quests. I have no description of what to do and instead I have this message :  "could not resolve any root: QuestDescription". Does anyone have a solution ?

[Dulhby]

Moreover on Debug log : exception loading list element from XML: System.MissingMethodException: Default constructor not found for type System.String 

[Ark]

It's great that you report bugs, but honestly you should read the sticky.
Sounds like you should post the save, and the whole log. If your game is modded, it propably should go to mod bugs instead, unless you can reproduce it without mods.