Gallery problem

[khenan]

Some of my photos don't open. It has a Grey picture of a gallery and then with a exclamation mark. What do I do??? How to I get my photos back??

[LaércioCJ99]

try to update gallery app on galaxy store

[NocommentXD]

It doesn't need an update but the glitch is still happening in my gallery 

[LaércioCJ99]

or restart

[NocommentXD]

How do I restart the app??? And every time I try to clear some photos on Google photos a whole months worth of photos get deleted from my gallery. And the same cloud with an exclamation mark is displaying over so many of my photos

[Kidacapp]

Are your pictures in your memory card or in the phone storage?