I got to the point where I'm supposed to go to elven capital to find clue for the princess. No matter what option I pick, I end up slap the princess but the quest doesn't update and I can't seem to progress further. The 'Meet Priestess' option also persist in elven capital and lead to infinite princess slapping loop.

I wonder if this is some kind of divine sign that says the princess deserves to be slapped for inciting an insurrection.

Seems like your game is quite outdated, it was a bug from earlier versions of 0.5.0

Thanks for the heads up! Didn't realize there were a few hot fix updates after 0.5.0 build.

By the way, using the newest build now and the dialogue with Duncan after delivering princess has a few typos:

'Once the princess' fate is ealed we will you the winner.'

At least I'm assuming this isn't some kind of accent he's supposed to have.