When you upgrade your android smartphone to the new version of Android OS, you may found some trouble appeared such as Facebook not working, Twitter can use, screen display some abnormal
You can study follow below instruction from developer.google page that there was advice you to roll back a version of Android by yourself. And you need to use more resource for solve this problem such as Adb tool (Android debug tool)
About your roll back version that need to flash system your phone again, please go to the instruction page from developer.google as below link
> Developer.Google
This site was fine explanation.
