Photos app on MacOS Sierra causes quitting unexpectedly upon opening

Problem came one after another on my old MacBook which showed a sign of data corruption for Photos app. First thing first, it was still on macOS Sierra but Photos app might have gone through recent update.

A message popped up when opening Photos app and required to have a repair on Photos' library since a recovery from time-machine backup. I wouldn't mind if it could fix it so I tried. After the repair operation, Photos app could no longer be opened again. Along with the crash, an error message said 'Photos quits unexpectedly'.

After reading a post about similar thing, it seems to be an issue of unmatched dynamic library causing Photos' crash.

/Library/Caches/com.apple.xbs/Sources/PhotoApp_SubFrameworks/PhotoApp-3161.4.14 0/lib/photolibrary/PhotoLibraryPrivate/PhotoLibraryPrivate.m:23

One explanation:

The cached version of a dynamic library is newer than the installed version. Try first to start your Mac in Safe mode to clear any caches, try to run Photos once in Safe Mode,see: Use safe mode to isolate issues with your Mac - Apple Support

To tackle compatibility issue of Photos app, two options are available:

1. Clear library cache in safe mode in the hope that Photos app will run again for further backup. But it looks like a temporary solution. I got a feeling that I might need to upgrade to macOS High Sierra for a remedy if there is something related newer Photos app.

2. Reinstall MacOS on top of running system (assuming the same version) in order to reinstall Photos app (as one of the builtin apps). Make sure a full time-machine backup is stored somewhere for recovery.

For option 1, it needs to clarify what is safe mode:

Safe mode (sometimes called safe boot) is a way to start up your Mac so that it performs certain checks and prevents some software from automatically loading or opening. Starting your Mac in safe mode does the following:
    Verifies your startup disk and attempts to repair directory issues, if needed
    Loads only required kernel extensions
    Prevents startup items and login items from opening automatically
    Disables user-installed fonts
    Deletes font caches, kernel cache, and other system cache files
If your Mac has an issue that goes away when you start up in safe mode, you might be able to isolate the cause.

So here's how to start up in safe mode:

1. Start or restart your Mac, then immediately press and hold the Shift key. The Apple logo appears on your display. If you don't see the Apple logo, learn what to do.
2. Release the Shift key when you see the login window. If your startup disk is encrypted with FileVault, you might be asked to log in twice: once to unlock the startup disk, and again to log in to the Finder.

To leave safe mode, restart your Mac without pressing any keys during startup.

For option 2, reinstalling an app which came with macOS by using reinstall macOS option in recovery mode does not erase user information. So, hopefully, those valuable personal information like photos and videos could be retained this way. Of course, it's absolutely important to have a full backup at first instance.