The newly released "Sniper Elite 3" appears to have no problem at all. In fact, the game has been receiving good feedbacks and comments from people. The game seems to be a little cosmic, having great graphics and great game-play.
Reports from Steam forums said that some of the consumers who had their pre-ordered "Sniper Elite 3" game keys cancelled. Maybe some purchased it from unregistered sources and when they were to play the game their key was blocked and discovering that their newly bought "Sniper Elite 3" is unplayable.
A community post from Rebellion said that it appears that someone took these "Sniper Elite 3" keys from one of their PC retail distributors without permission then sold it to other third party companies. Meaning it is either Valve or PC retail distributors are the one getting the money. But Steam instantly cancelled the keys. Because of this incident, many fans are upset of what happened.
Free "Sniper Elite 3" DLC
Maybe it is hard to believe, but this is true, Rebellion has offered the "Target Hitler DLC" free of charge to anyone who had their steam key blocked, even though they already get their refund from their third party seller. They were able to get their refund by just sending email to "firstname.lastname@example.org" with the receipt or proof of purchase from the vendor and the Steam key by Friday, July 4th. Rebellion suggested that if your steam key has been blocked, you directly contact the seller you bought from and ask for a refund. It appears that Rebellion is really doing the best they can to help those who are victims of the third party sellers.
For those who want to redeem the "Target Hitler DLC" free of charge, Rebellion posted the instructions on the community post. If you have further issues with the key, if would be better if you go to the seller you bought the keys from. But you can also contact Rebellion. Shop where you like but be warned with the third party sellers.