Hello tobyj42,
Thank you for contacting us with your issue. I have moved your thread to the Far Cry 4 forum in case anyone there can assist you further. I would also suggest that you contact the Ubisoft Support team directly for further technical assistance.
You can contact Ubisoft support through our ticket system's webform found by clicking on "My questions" on this page and then clicking "Ask a Question".
If you have any issues using the webform, you can contact support for assistance through their Facebook page, Twitter account or by phone.
Please try verifying your Uplay game files for Far Cry 4: https://support.ubi.com/en-US/FAQ/60...0000000ee85CAA
If this does not help, please contact our Ubisoft Support. Thank you. http://support.ubi.com