Restore Lost WeChat Messages After iPhone 6 Update To iOS 10.1.1

Having problem while trying to install the iOS 10.1.1 update on iPhone 6. After I press the update, and start the update process. It suddenly Popped up an error message and later, after I restart my iPhone 6, I found that all wechat messages were gone. Please help me to restore my lost wechat messages. They were important to me. Thanks.  It is quite obvious that this user lost all wechat messages during the process of updating iPhone 6 to iOS 10.1.1. We all know that accidents happen usua...