Please reset your friend list permissions for the game.
Please make sure to thoroughly read the instructions and look at the screen shot links(pictures may be from another game).
On a Desktop or Laptop PC
- Remove the app ( don't worry, your data will be saved )
This can be done by going to https://www.facebook.com/games/manage
Find the game and click the Gear button beside "Play Now" - http://prntscr.com/e6khep
Then on the bottom of that screen that pops up, click remove app - http://prntscr.com/e6kiad - Install the app again.
The Next 2 steps are important for your friends to show up in the game.
3) Click on "Edit This" - http://prnt.sc/ehn0lk
- Make sure the Friend list has the check like in this Screenshot – http://prntscr.com/ehn174
Changes may take up to 24 hours to be applied