stuck at transferring files



I’ve got an apple tv 2 which i have jailbroken with seasonpass and installed plex on it a couple of months ago.

Because i want to see .mkv files i downloaded atv flash. 

But i am stuck at transferring files then it says it can’t make a connection because of the internet ore firewall.The connection is good. the firewall i don’t know because of the internet of the neighbours which i am alolowed to use.

Can somebody help me?