I've just come across a rather annoying glitch on the Blackmail mission in Thief 2 which corrupts your save file, causing the game to crash upon loading it. I've looked around regarding the issue and it seems to be related to some buggy behavior by the sleeping guard in the guard room on the first floor (I alerted him and he tried running into the wall, then he froze completely). If this guard is alerted it seems that any saves created on the third floor of the house will become corrupt. It also seems to take a lot longer than usual to load uncorrupted saves on the mission once this has been triggered.

I've no idea why it only affects 3rd floor saves or the reason it's caused by this one guard but so far the only solution I've found (from older threads found online, not tried re-doing the mission again myself yet) is to restart the level and avoid the guard completely.

Edit: I've replayed the mission now without doing anything to the guard in question and was able to save and load normally.

Hey clutton,

I just wanted to thank you for this post. Not sure you'll see this message or not, but I figured I'd try. :P

I just literally 5 minutes ago encountered this exact bug, and you were the only Google result for it! It was just as you say- I found that buggy sleeping guard, and tried knocking him out. When that didn't work, I carried on, thinking nothing of it.

When I went upstairs past the two guys who mention the lightswitch, my quicksave corrupted itself permanently, and my only choice was to restart the mission.

Thanks for the time you spent investigating this issue. Wish there was a better solution, but oh well!

Take care :)

I signed up to thank you! You did some great investigation work! As soon as I got to the part where I found out that [SPOILER!!!!!!!!!!!! the sheriff died, I had to go to work so I saved the game and exited.

That is when I encountered this glitch, I first thought it was a simple bug and I restarted the game twice and loaded the same save slot twice and still had the same result. I restarted the computer and still the same result.

All the other save game files worked fine!!! I then restarted the level and Googled about this issue. Luckily I found this article and I remembered EXACTLY the guard in the guard room spinning around and that lil glitch.

Thanks homie, I am now playing it on the Normal difficulty [was doing it on expert when I first encountered the problem] and now am at that guard room. However I don't see the guard. I loaded a save I created on my second playthrough of this level and still no guard on any of them. I was wondering the guard was only in the two latter difficulties.

Exactly 10 years later, this post helped me too, I'm glad it exists.

Its probably documented somewhere on an official fan site and probably is fixed by tafferpatcher, but I'm running on an old Windows XP machine with an actual CRT monitor, they way it should look (colours are way better with the lights out) and running the patches seemed to upgrade the game in a way that it would no longer run with this old AGP video card. So persevering with the original state of the game.

One day when I'm playing on an OLED monitor I'll fully upgrade the game and play it on a modern system :)

But I knew the game was running too slowly on the 3rd floor, even on this old computer, there was no reason for it, these original levels are very well optimised. I'd say this guard bug triggers some kind of memory leak, and some kind of objects to do with AI are being created infinitely, taking up memory and resources, slowing the game down, till it crashes, even saving all this garbage data to the save file which is why it takes so long to load.

But because I like to keep very few save files to keep the tension up, I ended up having to play the entire mission again. Was fun speed running back to where I was up to anyway, didn't take long. Most of the time playing Thief is playing cautiously when you don't know what will happen ;)

the latest T2 GOG build should still work on win2000 as long as you do not apply any 3rdparty upgrades, so xp shouldn't be a problem.