For anyone with the Gallery crashing issue. This is how I fixed it:
1) Open 'Gallery' app info
2) Under Permissions, make sure 'Location' is set to 'While using app'
3) Try and open Gallery app again. If it works, great. If it crashes again, go to step 4.
4) Under Developer options: Make sure 'USB Debugging' is on. Make sure 'USB Debugging (Security settings)' toggle is set to ON. Connect phone to PC.
5) Open ADB and run: adb shell pm clear com.miui.gallery
6) Repeat steps 1 - 3.
7) Should now work.
Hope that helps.
Note to devs: The Gallery app only has a "Clear cache" option in App info. Maybe a "Clear data" could solve this without the need for adb?