Monksnothome

This happens for any dayz not just epoch even just the DayZ Mod itself do you know how to fix the error.

Can someone please help me with this. I have been doing everything i can for the past three days now trying to get the DayZ mod to work. When ever i join a server it says remove listed files, or install additional keys. I have removed the files and it asks for the same files after i deleted them from my computer. Here is a screen shot of the error i get trying to join DayZ Epoch Namalsk server. Please can someone help me!!!!!