omidksm
Hi there,
Thanks for your feedback.
DLNA doesn't support external subtitles. If you play videos over DLNA, you will not see the external subtitles. We recommend you to use SMB and AirScreen(SKYBOX PC Client), then you will see the external subtitle files.
You can go to our website to download SKYBOX PC Client(AirScreen) or set up a SMB shared folder on your PC.
Best regards,
Lucy