The FLT release has a custom steamclient.dll that conflicts with modern Windows security.
When the game client fails to communicate with the environment, it usually results in a silent crash. Direct X and Redistributables sonic generations cracked steam client not running
Sometimes the installation process fails to copy the crack files correctly into the main directory. Open your game installation folder. Look for a folder named "Fairlight" (depending on your repack source). Copy all files inside that folder and paste them into the main Sonic Generations directory, choosing to "Replace" if prompted. 3. The "Demo Folder" Workaround The FLT release has a custom steamclient