Sunstone quest bug

[bbderek]

Not able to complete Battle Preparations, The Sunstone Quest. Philippa will not open the door to the Elven ruins. She does nothing when approached at the door of the ruins. Attempted to talk to Philippa, she only responds with "Witcher." On first attempt, this was after completing all other quests for the Battle Preparations. Then loaded an earlier save, just after having completed Final Preparations, and tried Sunstone Quest again, prior to any of the other Battle Preparations quests. Same result. Has anyone else experienced this? Does anyone know how to fix or work-around this bug?
Thanks

[bbderek]

Fixed it. Used Steam 'verify integrity of game cache' (local files tab of game properties). "1 file failed to validate and will be required." Philippa then opened the door and was able to proceed with Sunstone Quest.

[songs about bane]

decade revial ik
reason of state was my problem or at the very least my solution. was trying to do it last, reloaded before sailing to phil, did reason of state and when meeting her things went as they are supposed to

not sure if it's the reason for the bug or just reloading philippa fixed it... hope this helps a few on the path... this one is a bethesda type game breaker (mission is essential to final act)