MPI_Recv() invalid buffer pointer - parallel-processing

Question

I have a dynamically allocated array that is sent by rank 0 to other ranks using MPI_Send()
On the receiving side, a dynamic array is allocated memory using malloc()
MPI_Recv() happens on the other ranks. At this receive function, I get invalid Buffer Pointer error.
Code is conceptually similar to this:
struct graph{
int count;
int * array;
} a_graph;
int x = 10;
MPI_Status status;
//ONLY 2 RANKS ARE PRESENT. RANK 0 SENDS MSG TO RANK 1
if (rank == 0){
a_graph * my_graph = malloc(sizeof(my_graph))
my_graph->count = x;
my_graph->array = malloc(sizeof(int)*my_graph->count);
for(int i =0; i < my_graph->count; i++)
my_graph->array[i] = i;
MPI_Send(my_graph->array,my_graph->count,int,1,0,MPI_COMM_WORLD);
free(my_graph->array);
free(my_graph);
}
else if (rank == 1){
a_graph * my_graph = malloc(sizeof(my_graph))
my_graph->count = x;
my_graph->array = malloc(sizeof(int)*my_graph->count);
MPI_Recv(my_graph->array,my_graph->count,int,0,0,MPI_COMM_WORLD,&status) // MPI INVALID BUFFER POINTER ERROR HAPPENS AT THIS RECV
}
I dont understand why this happens since memory is allocated in both sender and receiver ranks

Answer 1

Below is a minimal, working, and verifiable (MWVE) example which Zulan suggested you to make. Please provide MWVE in your future questions. Anyway, you need to use MPI datatype MPI_INT instead of int for sending and receiving.
#include <mpi.h>
#include <stdlib.h>
#include <stdio.h>
typedef struct graph{
int count;
int * array;
} a_graph;
int main()
{
MPI_Init(NULL, NULL);
int rank;
MPI_Comm_rank(MPI_COMM_WORLD, &rank);
int x = 10;
MPI_Status status;
//ONLY 2 RANKS ARE PRESENT. RANK 0 SENDS MSG TO RANK 1
if (rank == 0){
a_graph * my_graph = malloc(sizeof(a_graph));
my_graph->count = x;
my_graph->array = malloc(sizeof(int)*my_graph->count);
for(int i =0; i < my_graph->count; i++)
my_graph->array[i] = i;
MPI_Send(my_graph->array,my_graph->count,MPI_INT,1,0,MPI_COMM_WORLD);
free(my_graph->array);
free(my_graph);
}
else if (rank == 1){
a_graph * my_graph = malloc(sizeof(a_graph));
my_graph->count = x;
my_graph->array = malloc(sizeof(int)*my_graph->count);
MPI_Recv(my_graph->array,my_graph->count,MPI_INT,0,0,MPI_COMM_WORLD,&status);
for (int i=0; i<my_graph->count; ++i)
{
printf("%i\n", my_graph->array[i]);
}
}
MPI_Finalize();
return 0;
}