C++ Weird error. Fails to compile - c++

Question

I have been using the allegro 5 libraries for developing a game in C++ for some time. Today I got some weird error:
I have a class called level. I have a header file called levelhandler.
Here's how it looks:
#pragma once
#include "level.h"
level level_1;
level *currentlevel;
void initialize_levels()
{
currentlevel = &level_1;
}
When I try to compile it gives me strange errors like:
error C2086: 'int level' redefinition
error C2143: syntax error : missing ; before 'level_1'
I remember that it could compile before, and I did use currentlevel->Player.X a lot of times, but now I have a lot of that and it gives errors like these:
error C2227: left of '->Player' must point to a class/struct/generic type
error C4430: missing type specifier - int assumed
header pasted from comment
#pragma once
#include "entity.h"
// some more includes
class level {
public:
enum Tileset { ... };
enum Tile { ... };
int tiles[200][200];
player Player;
level(void);
~level(void);
};

Answer 1

Such errors are hard to find as long as you look at the "Error List" pane. Select View/Output to show the "Output" view. The line after the error C2086 shows the original definition of level.
You fill find an
int level;
there as the C2086 tells you. If it's the line
level level_1;
of your fist example you will have to check the last header file include in your compilation unit. It might end with an int or it has a unbalanced #if clause.
To find the exact location start using a Short, Self Contained, Correct (Compilable), Example. This helps you to find the bug and saves time of other with their crystal balls.
Edit:
Another way to find the reason for this unexpected behavior is to see the preprocessor output. Set the Generate Preprocessed File option int the C/C++/Preprocessor project property page to With line numbers (/P) and look in the generated <sourcefile>.i
Check that that level.h file has included what you intended.

Answer 2

Ok, so I've been tinkering around with my project the weekend, and I finally found out what whas the problem that gave me so many weird compiler errors. It seems that I had a lot of cases where two header files were including each other, and the compiler really didn't like that, so I corrected that, and now I'm ok. Thank you all for helping me, and have a great day!