Hey in0,
That is definitely the issue.
When I go into the documents/Arduino/hardware Folder I have an anet configuration.h and when I browse it the line you indicated is there.
When I go into the ardinuo PGM and browse the configuration. H it does not have the line.
Not sure what happened. I will uninstall everything and redo it to see if that fixes the issue.
I will let you know how it goes