Anyway when I added a few new files to the project, they were added as C++, because the default was C++. Since the files were actually C, GCC generated a LOT of errors, most of them not making any sense whatsoever.
Now that this issue was solved, I am working at some functions to calculate and log the number of human players in every map, and print that number along with the percent of the total players in that map. This will be a very useful tool because we'd like to know exactly which maps are the msot empty, so that we can add some 'touristic attractions' there, in order to encourage the players to visit them.