There are two ways to solve these issues,
A. Roll back to Windows phone 8.1
B. Hard reset
I would suggest you to try hard reset if you're hard core windows 10 user.
A. Roll back:
- Download and install the Windows Phone Recovery Tool in your desktop
- Select your phone and it will download the appropriate installation package (Windows phone 8.1) to your desktop (download size > 1.5 GB)
Read this article for roll back to Windows phone 8.1,
I have seen some of the user comments saying rollback getting failed and screen becomes dark (may be device got bricked).
B. Hard reset:
It will not just reset your device; erase all your phone data and re-install the OS
Try soft reset; Press Volume down + Power button. If it doesnt solved your problem then try hard reset.
Take backup before proceeding the hard reset. Microsoft will restore your backup when setup your device. If you skip the restore process remember you cant do the same again.
Go to Settings -> System -> About -> Reset
Hard reset solved the issues for me. It works.