Before completing please check that the time, date and timezone have been correctly set on the device running the Player.
To be completed by the original poster:
Player Version
version 2 r255.3
Issue
One player stopped playing an MP4 file in a layout. Now CMS shows updated and all good, but player shows splash screen, then goes to black. MP4 is 50MB, but downloads only show 535B downloaded…
Provide screenshots where possible!