Minecraft server wont connect?

hello, I'm new to the whole owning my own server thing and i set one up a while ago and it worked fine but minecraft has been updated so i downloaded a jar file for the 1.8.8 server so its the same as minecraft but when i open multiplayer it try's to connect to my server but then after a few seconds red writing appears under the server name and it says "cant connect to server"

Can anyone help please, it'll be much appreciated.

Thanks in advance.

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