If CLion can't resolve iostream, check your CMake version

I recently upgraded fedora to Fedora 28 and I got a strange error in CLion:

 As you can see, this is a simple hello world project. Nothing fancy. If something like this happens to you, check Settings | Build, Execution, Deployment | Toolchains Check Environment test as  Anastasia Kazakova explains.

In my case, I have CMake 3.10

However, when I looked at my CMakeLists.txt it said 3.9. I changed it to 3.10 and everything works properly now.

 cmake_minimum_required(VERSION 3.10)
project(765)

set(CMAKE_CXX_STANDARD 17)

add_executable(765 main.cpp)

All I needed to do was reload the project as CLion prompts me:

Happy C++!