In cases where built-in Microsoft applications (such as photos, sticky notes, calculator, etc.) no longer open, they can be repaired by following these steps:
(This example can be used for any built-in program)
Open the start menu and search for the app in question, then right-click for more options. Select "app settings".
Scroll down to the Reset section and click repair. If the app still doesn't open after you've clicked repair, then click reset.