The "Unable to open bigfile.000" error in Rise of the Tomb Raider
Check Antivirus/Firewall Permissions: Your security software may be blocking the game from accessing its own files. Add an exception for the game's executable and its main installation folder .
This is the most effective fix. It scans for missing or corrupt files and redownloads them. Right-click the game in your library > Properties Installed Files Verify integrity of game files Epic Games: Click the three dots next to the game > Adjust Permissions and Compatibility
Benefits:
Epic Games Store: Click the three dots under the game tile > Manage > Verify.
If you've encountered the frustrating "Unable to Open Bigfile.000" error while trying to launch Rise of the Tomb Raider , you aren't alone.
What is bigfile.000?
Before fixing the error, it helps to understand the culprit. In Rise of the Tomb Raider (and many modern games), developers pack game assets (textures, sound, scripts, and cinematics) into large archive files to improve loading times and organization.
The "Unable to Open" prompt can signify a failing sector on your Hard Drive or SSD. Open Command Prompt as Administrator.