Network error message when trying to play videos

[Gosfox]

Having problems playing videos on my cloud using a Samsung android device
All mp4 format which have played ok in the past ,I get a message as follows
Cant play video -your phone has disconnected from the network -connect to a network and try again ,selected jpegs show ok ,network connection is ok and ipad 2 works ok with my cloud device on the same network,
Anybody come across this problem?