How can I load text from file with blueprint?

Hello, i have no clue about c++, but i would like to load a string from a file into the engine with blueprints.
Following this instructions, i have added a new c++ class “yourBlueprintFunctionLibrary”, added the code at the end of the *.h and *.cpp file.
When compiling, i am getting an error “no class or namespace”,
in Microsoft Visual Studio Express 2013, i see

What am i doing wrong? I am working on 4.83, windows 8 64bit.

Thanks in advance