In the future, please keep DLC-related questions to the DLC page!!
It also looks like you've installed the DLC incorrectly. The folder name should be "14 Nights With You", not "14nightswithyou-free". You'll need to locate the correct folder and use it to replace the "14nightswithyou-free" folder instead.
If you still need help, please leave a comment on the DLC page and I'd be happy to assist further ^^