Hello everyone,
I understand some of you are having trouble with Synergy since the recent Valve update (SteamPipe).
This update changed some things around for Half-Life 2, Episode 1 and Episode 2.
You can try to correct this problem by launching the Valve games first, again to reinitialize the games' files.
This should get Synergy working again.
Hope it helps! If not, post here and we'll figure it out!