Hi Yassi,
You did not give us the website information to check the case to follow up. Please, backup your website completely and update the theme to version 6.1.6 and Cornerstone to version 3.1.6.
Also for the Posts Carousel please make sure that you set at least one post to be featured. If you set the options from the X > Theme Options to have only featured ones you need to have featured posts. If you do not have featured post there will be a blank carousel.
kindly get back to us with the result of the steps above and URL/User/Pass of your WordPress dashboard using the Secure Note functionality of the post to follow up the case if you still have problems.
Kindly open up new threads for additional questions as it will help us to focus on each issue and give you a better support which you deserve. Having a long threads makes the maintaining job harder and also it will be harder for the other customers to find the correct information if they have similar issues. You are always welcomed to reply to this thread to follow up the same question.
Thank you.