If you are trying to launch Serious Sam 3: BFE only to be greeted by a black screen or a crash with the error you are not alone. This is a common issue with the Serious Engine 3.5 when it fails to handshake with your monitor's resolution or refresh rate.
Use the AMD Cleanup Utility or DDU (Display Driver Uninstaller) to wipe old drivers before installing the newest Adrenalin software. 🛡️ Fix 5: Run as Administrator and Compatibility Mode serious sam 3 cannot set display mode
Look for a file named Sam3.ini or User.cfg (if not there, look in userdata under your Steam installation folder). Open the file with Notepad. If you are trying to launch Serious Sam
Search for the following lines and change their values to match your monitor: gad_iPosX = 0; gad_iPosY = 0; gad_iWidth = 1920; (Change to your monitor width) gad_iHeight = 1080; (Change to your monitor height) Save the file and restart the game. 📺 Fix 3: Lower Your Monitor Refresh Rate 🛡️ Fix 5: Run as Administrator and Compatibility
Go to your Steam library, right-click Serious Sam 3 > > Browse local files .
If it loads successfully, go into the in-game video settings, set your correct native resolution, apply it, and then you can safely switch back to fullscreen. ⚙️ Fix 2: Manually Edit the Configuration File