It's your Smartphone so did my mom's cell phone, she lit it and erased it all, playing it again "Defaults" is in Settings> Factory Reset> Erase everything.
After that and when you turn over, you remove the cover to your cell phone, You extract the SD card or memory is, take it off for a while, If the problem persists and touches you buy a new Tajerta SD because suddenly card has flaws but it's better to buy a new SD card I recommend a Kingston are good, there is no other solution my mom did not work several solutions and the solution is to buy a new SD card new.
Greetings! Hope this can help you.