Android Question

To whom it may concern.
I need help with my Samsung galaxy S4. I inserted a microsd 64Gb, class 10, card into my device. I had ran out or storage space. All was well. I tried to move all my 24 home videos of my 6 year old son from the phone to the microsd card. It took a while but they all moved to the storage card. I found out that only 10 worked out of the 24. The other 14 wont play. They keep getting