I knocked out the guard on the balcony and entered. Knocked out those four guards inside. Snatched that letter, keyes and...it WORKED!
Needless to say, I didn′t used that downloadable content (Rat pack - I think at least...didn′t appeared after sleeping.
I′ve heard about different problems, like freezing in other parts. Hopefully it won′t happen. And If, I try to download the patch. However, I will write if I encounter any problem.
I have question about missions - when I, for example, retry every mission with no killing, then I will have "Clean hands" in the end? Thank you.