My Mac displays the log in screen for entering password, but after entering and when the progress bar hits around 40% it will show the “your Mac will restart because of some problems...” and when it restart it will again enter this status, so it is like a never ending loop.
This might be a problem: hard drive only have 8.7 MB free space.
It is due to the low disk space. After deleting the Window Boot-Camp which provide an extra 64GB on disk, my Mac successfully booted.