UE4 SlateWidget create C++ file hot reload failed

hi everyone, i have a problem like this.When i create SlateWidget from UE4 Editor,it say like this:

286691-111.jpg

and the output log :

when i go to vs and recompile the project :

so what shoud i do???i do not understand sometimes i create the cpp file success which in the editor,but today i failed all the time