The breakpoint will not currently be hit - No executable code is associated with this line

Hi, I’m learning the EQS system and interested about how to make it by C++, so I want to debug engine source code in Engine\Source\Runtime\AIModule\Classes\EnvironmentQuery\EnvQueryTypes.h. I have already download editor symbol. But when I attach VS to the game project and run the game, I get the error like below:

I don’t know how to solve it. Could anyone help me? Thank you very much!