Don't do the quests. Horribly broken and very minor improvements since launch. They are trying to design quests in an emergent world and its very hard to do properly so you get things like this.
If your quest doesn't crash something unexpected happens. One time I had an escort quest and the caravan IMMEDIATELY turned back into town since it had so few men and just sat there forever.
TW should just remove all these quests and stop trying to do them. You've had almost a year and still horribly broken. Just take them out.
I did and i won... (quest caravans) with an army sometimes (new strongers troops conspiracy, difficult, but very good) !!!
But if they are too far away, I don't. These quests are done, I think, when they are adjusted, made to aid players in their progress and also to introduce "bosses" into the game to kill. And probably also to deepen the Role Play. I do them, sometimes I lose, but it doesn't matter. I did a lot, there were any big crashes, not many, and I know it's a work in progress.
TW has progressed a lot, the rhythm of the quests is more "regular" and often occurs during periods of peace ((sometimes during a war, but my husband and my sister-in-law go to war for me). So, I continue to play these "conspiracy quests", my goal is to discover all the facets of the game, and as long as participating in an EA, I might as well play the game ...