I am learning C and getting into structures, but I am getting a lot of errors I don't know how to fix.

I am using xCode, and I've made a header file. This is what I have in my header file:

Code:
struct player {

int playerID;
char rank[25];
char fieldType[25];
int level;


};


The first error I get is "Type 'struct player' has incompatible definitions in different translation units".

I've already included the header file and <sys/player.h> in the main editor. So far, this is what I have in my main editor:

Code:
 #include <stdio.h>
#include <stdlib.h>
#include "Header.h" (this is the name of my header file)
#include <sys/player.h>

int main () {

struct player newbie;

newbie.playerID = 10;
printf("Enter the RANK of player 10: ");
gets(newbie.rank);
printf("\nEnter the FIELD TYPE of player 10");
gets(newbie.fieldType);
printf("\nEnter the LEVEL of player 10");
gets(newbie.level);


return 0;
}

Then I got these errors:
No member named 'playerID' in 'struct player'
No member named 'rank' in 'struct player'
No member named 'fieldType' in 'struct player'
No member named 'level' in 'struct player'

What am I missing?