While i am playing candy crush on my phone there are showing error last 4 days and no syn with fb

Make sure you have a stable connection. If that didn't work, here are the steps to solve:

1. Log out Facebook
2. Then clear cache of your facebook and wait for 30 seconds
3. Log in Facebook.
4. Open the game then log in into facebook account.

Please delete then reinstall candy crush and facebook first, then, log in into Facebook account, and lastly, log in into facebook in Candy Crush.