LittleTijn: Found a fix for the error message "Duplicate CD Keys found" when trying to start a multiplayer session with the GOG version of Chris Sawyer's Locomotion!

By adding a CD key to your Windows registry, the check will succeed!

Just follow these steps:

- Press and hold the Windows button and press R. This will open the "Run" dialog.
- Type regedit.exe in "Open" and click "OK". This will open the Registry Editor
- Navigate to the following key:

For 64-bits Windows:
HKEY_LOCAL_MACHINE\SOFTWARE\WOW6432Node\Microsoft\Windows\CurrentVersion\Uninstall

For 32-bits Windows:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall

Create a new key in the "Uninstall" key with the following name:
{77F45E76-E897-42CA-A9FE-5F56817D875C}

- Open the newly created key.
- In this key add a String Value (REG_SZ) by clicking on "Edit" in the menu, pointing to the option "New" and clicking on the option "String Value"
- Give the new value the name:

CDKey

- Double click the new "CDKey" value to change it value.
- Type a unique value in the text box "Value data". The value of this String Value can be anything. As long as it is different than the other player.
- Click on OK.
- Close the Regsitry Editor

After that, you can run the game in multiplayer!

See the attachment for a example with a 64-bits version of Windows.