A lot of my files getting corrupted after being transferred from Galaxy J3 to SD card. Why?

[Android Central Question]

First time having this problem.. Every other phone I've had, has never had issues transferring files to ad card and them getting corrupted. So I'm bout to just buy another SanDisk.. But I wouldn't mind knowing what side the problem lays. I've never bought an SD card from a cell store prior to this one, the Kingston brand either. Kingston 16gb being the one I got. So first time using this Galaxy J3 and The Kingston brand sd card, bought at a lil authorized dealer cell store. So I'm trying to pinpoint the source.. Simply put, I moved music and photos from internal to sd. And the result being 60-70% of the files now have an unknown error and cannot be opened by any multimedia apps. So as a result I reformatted the sd card, tried transferring stuff again... and same result. So why am having this problem now with the phone and sd card I'm currently working..? Kinda irritating when what has always been a mindless transfer process , is now a trek through a battlefield. Let's see what files make it through this time... Lol. Any ideas.. That could lead to some actions.. That with trial and error could lead to a solution? Lol

 

[Rukbat]

It could be a problem with the J3. (Samsung had a problem with the S3 that destroyed cards.) But the store should give you credit on the card towards a SanDisk card. (SanDisk is the one that came up with the fix to the mess Samsung had caused.) At least with SanDisk, even if the problem is the phone, they'll probably try to find a way around it. If the problem is ever with their card they'll replace it if you contact them online (SanDisk microSD Tech Support upper right - live chat).