Warning-STEAM message "We've come up empty"

[Fjordmonkey]

Here's what I'd try (you've probably already done so, but I'll say it regardless.

1: Go into your steam-folder and take a copy of the folder named Common in your Steamapps-folder (\steam\steamapps\common). This will allow you to NOT have do download the entire game again. Mind you, this folder will be huge if you have a lot of steam-games installed.

2: Uninstall Steam, delete the Steam-folder afterwards (but keep the copy of your Common-folder).

3: Reboot your computer, and reinstall Steam. Shut down Steam afterwards.

4: Copy your old Common-folder into \steam\steamapps. If it warns you about files being present, overwrite them.

5: Restart Steam, go into your Library and check if there's any games in the list.

If CLoD shows up, right-click it, choose Properties, Go to Local Files and do both a "verify integrity of game Cache" and Defragment Cache Files".

If not, you will have to deal with Steam Support. Reinstalling the game from discs will NOT work, as you will quite rightly get the message that the CD-key is already in use, which is also correct behaviour when it comes to Steam due to the link between your account and your CD-keys. You can, if you so choose, redownload the game through Steam, but only if the game shows up in the first place. Might not be an option for people with slow connections or bandwith-limitations, however, as the installed game takes about 3.3Gb of diskspace.

This might be a long-shot, as it's the first time I've seen that particular issue. Usually Steam is on the ball when it comes to Support (last time I had to contact them it took them about 2 days after I had sent in the info they requested and until the issue was resolved), but results might differ.