XCode 8.3.3 lot's of errors

I’m just testing out a simple Advanced Vehicle C++ template in Xcode. The code seems to compile despite the fact that Xcode is full or red errors:
They all seem to be _Index target. After some time they go away but when I try to write some code they appear again. For example when I try to write:
it is recognized and I get some code suggestion but I do not get anything afterwards. Seems like developing Uneal games in Xcode is either very hard or not possible.