I made a mistake in the first post but in my program it is rigth, well the program is:

typedef struct _LONG_ADDR
{
BYTE v[8];
} LONG_ADDR;

typedef struct _SHORT_ADDR
{
struct _SHORT_ADDR_bits
{
BYTE MSB;
BYTE LSB;
} byte;
WORD Val;
BYTE v[2];
} SHORT_ADDR;

typedef union _ADDR
{
LONG_ADDR LongAddr;
SHORT_ADDR ShortAddr;

BYTE v[8];
} ADDR;

could it be
you are making a union of two identical entities

LONG_ADDR contains BYTE v[8]; and you repeat that in the union, just as a test try removing BYTE v[8]; from the union, if that works, experiment from there.

Erik

Hi erikm thanks for yours proporsals!

I think that I have found the solution, the problem is not the definition of the "typedef struct" inside of another type struct. The problem is that I am calling the #include "file.h" where the LONG_ADDR,SHORT_ADDR and ADDR are defined twice. I have made the experiment only with the main with only #include "file.h" and nothing more and everthing was rigth, no errors. But after I tryed put the sentence #include "file.h" twice

#include "file.h"
#include "file.h"
void main(void)
{}

then the error appears.
My program have some files and maybe I am calling #include "file.h" in two diferent files and this files are called from the main too.

have you tried what many do (I do not)

for every .h file you write

#ifndef HFILENAME
#define HFILENAME

the guts of the file

#endif

That way any .h file will only be included once, however you make your code

Thanks again Erikm!!

I usually do this (put #ifndef HFILENAME ....) with my "xxx.h" files but this time I didn't and I think that will save me time.

Thanks

Santi