This forum is for the Unreal 4 engine. You should post your problem in the UDK forum here.
Epic recommend anyone starting a new project to give the UE4 engine a try.
As PuckerFactor said, please post this into the UDK forum.
But to give you a fast reply ;): As you can see from the error, two same files are existing in different folders. e.g For the first one you have to go to Engine/Content/ and there you will have to delete or rename Entry.upk.
Thanks PuckerFactor for making me aware of the forum difference.
And thank you as well fighter5347 for that info. I’ll give it a shot when I get home tonight.