How do I fix Fallout New Vegas error code 51?

Alton Alexander
By Alton AlexanderUpdated on June 4th, 2022

When trying to launch Fallout New Vegas, some players may encounter the error code 51. This is caused by a conflict with the game's launcher and the Steam client. To fix this, you will need to add an exception for the game's launcher in your Steam client's settings.

1. Restart your computer and try again

  1. Restart your computer.
  2. If the problem persists, try reinstalling the game.
  3. If the problem persists, try verifying the game cache.
  4. If the problem persists, try contacting support.

2. Delete the Fallout New Vegas folder in your Documents folder and try again

  1. Open the Documents folder.
  2. Locate the Fallout New Vegas folder.
  3. Right-click on the Fallout New Vegas folder and select Delete.
  4. Wait for the confirmation message that the deletion was successful.
  5. Try reinstalling Fallout New Vegas.

3. Verify your game files through Steam

  1. Open Steam and click on the Games menu.
  2. Select your Fallout New Vegas game from the list.
  3. On the right-hand side, under the "Tools" tab, click on the "Verify Files" button.
  4. Steam will now scan your game files for any errors. If it finds any, it will display a message along with a code number.
  5. To fix the error, you will need to find the corresponding code number and follow the instructions that it provides. For example, if the code number is 51, you will need to go to the Steam folder inside your Fallout New Vegas game folder and delete the "FalloutNV.ini" file.

4. Try running the game in compatibility mode

  1. Launch Fallout New Vegas.
  2. Click on "Settings" on the main menu.
  3. Click on the "Options" button.
  4. Under "General," click on the "Compatibility" tab.
  5. Check the "Run in compatibility mode" box.
  6. Click on the "OK" button.
  7. Close Fallout New Vegas.
  8. Start the game again and ignore any errors.

5. Try running the game as an administrator

  1. Navigate to "C:\Program Files (x86)\Steam\steamapps\common\Fallout New Vegas"
  2. Right-click on "Fallout New Vegas.exe" and select " Properties "
  3. Click on the " Compatibility " tab
  4. Check the " Run this program as an administrator " box and click on the " OK " button
  5. Click on the " Play " button to start the game

If you didn't find success with an option above, then try:

  1. Reinstall Fallout New Vegas.
  2. Disable any mods you have installed.
  3. Try using a different save file.
  4. Try starting a new game.
  5. Contact Bethesda for support.