Do still photos taken with the same card show up OK ?
If so, the SD card may not be the culprit.

You might try playing the videos with VLC Media Player.
It is a free download that I have used for years.

I haven't run into any video that it won't play.

Myron

Last edited by speedsixman; 09/25/16.
How many peckers can a Pecker Checker check if a Pecker Checker could check peckers?
(stolen from shootinurse)