Crash when viewing bandit quest window after using Book of Reform

I have used the Book of Reform to gain an additional Frenzy Charge (instead of an Endurance Charge).
After that, the game crashed with an exception saying "invalid string position".
When I open the quest window (with U) and click on the quest "The Bandit Lord Kraityn" the game crashes again with the same message. 100% reproducible for me.


Here is the bug report screenshot:

I've actually gotten the same "invalid string position" crash when landing the killing blow on both Oak and Kraityn each.

I don't know if any of the following is relevant to the issue, but I include it just in case:

Warband SC Normal.

I chose to help Alira.

I had the quest from each of the bandits to kill the others.

I opened, but had not yet entered, the Vaal Ruins previously.

Again, this crash happened twice. Once each when landing the killing blow on Oak and Kraityn.

If any additional information is required, I will be happy to provide.

EDIT: I am running Windows 10, not sure if that makes a difference.

I have a similar issue, and I have not used a Book of Reform. I killed all the bandits long ago, so I dunno if it occurs when landing the killing blow.

I thought it had something to do with the "Through Sacred Ground" sidequest.

Character "Razitan" crashes when I click to view a certain act 2 quest in Merciless only. (I can't recognize the quest name from its icon.)
Razitan has not completed "Through Sacred Ground" quest in Merciless.

Character "VandiAlvan" crashes when I click to view a certain act 2 quest in Normal and Cruel, but not Merciless.
VandiAlvan has not completed "Through Sacred Ground" quest in Normal. I may have completed the rest of Cruel before I did this quest. I'm pretty sure I did this quest in Merciless while doing the rest of the Act 2 quests.

Razitan helped Oak on Normal, and killed all bandits in Cruel and Merciless.
VandiAlvan helped Oak on Normal, killed all bandits in Cruel, and helped Kraityn on Merciless.

VandiAlvan definitely met all the bandits and climbed the Vaal pyramid in Normal before killing any of them. She probably killed the bandits in the order she met them (without meeting anyone else) in Cruel and Merciless.

I have not used the "Book of Reformation" vendor recipe at all.

Razitan crash video (normal): https://youtu.be/QFnpnWe25xg
VandiAlvan crash video (cruel): https://youtu.be/Q2GUx9l9JeI
VandiAlvan crash video (normal): https://youtu.be/fNHMU7jFfRQ

"Exception: invalid string position": http://i.imgur.com/9NEljB4.jpg
Generic "Runtime Error": http://i.imgur.com/iSh3wei.jpg
The problematic quest is to the right of the highlighted quest.

I have not tried re-downloading the entire client/ggpack.
Edit: Uninstalled and re-installed. No change.

same here with kraytin
(at first I chose to help him, then killed the other two, and then decided to also kill Kraytin)

--> popup with "invalid string position" and game crash.

After restart, the amulet was at the floor and I could complete the mission.