Why am I getting the error message Unfortunately, Samsung Galaxy has stopped.?

[AshKnipler]

"Unfortunately, Samsung Galaxy has stopped."

Whenever I enter Gallery a sign pops up that read "Unfortunately, Samsung Galaxy has stopped." The home button doesnt work while the sign is up. However, after clicking "Ok", Gallery works fine and has no flaws. If I leave and re-enter Gallery (even if I havent shutdown the app), the sign will pop up again. It started appearing in the last 3-5 days. Help anyone, please?
Oh and I havent rooted my Android. And I havent installed the latest Lollipop update, as I dont want to lose 3Gb of space for a few little upgrades.

 

[timandra]

Me too. Also battery draining now very quickly and mediaserver using 47% of battery. Have had no good replies yet.

 

[Dotsom Som]

Whenever I enter Gallery a sign pops up that read "Unfortunately, Samsung Galaxy has stopped." The home button doesnt work while the sign is up. However, after clicking "Ok", Gallery works fine and has no flaws. If I leave and re-enter Gallery (even if I havent shutdown the app), the sign will pop up again. It started appearing in the last 3-5 days. Help anyone, please?
Oh and I havent rooted my Android. And I havent installed the latest Lollipop update, as I dont want to lose 3Gb of space for a few little upgrades.