Videos play problem - Coby Kyros mid 1024

[lince55]

I can´t play videos stored in the external sd card.
I tried with the default software, MX player and BS player.
The playes begins to load the video for a while, close and returns to main screen.
However, all players plays the same files smoothly, but stored in usb pendrive.

Can you help me?

Thanks in advance

Lince