Problem adding class from editor

Hi, I’ m trying to add a class to my project from the editor exactly like how it is done in the documentation
https://docs.unrealengine.com/latest/INT/Programming/QuickStart/3/index.html
or in the ue4 c++ introduction videos.

Both the header and the source file are successfully created, but the source file contains only the #includes, without “MyClass::MyClass() {}”.

So, i try to add it manually, but, when i try to compile, i get this error
“error C2084: function ‘MyClass::MyClass(const FObjectInitializer &)’ already has a body”.

I hope someone could help me, since i have no idea of what i’m doing wrong.

PS: sory for my english.