Unable to read memory. Can't find what's wrong - c

Question

I've got a piece of code, it's purpose is to draw a background image on one of the game levels. For this purpose I create this structure.
typedef struct crate_t {
int x = 0;
int y = 0;
int h = 0;
int w = 0;
int type = BACKGROUND;
}crate;
Then in the main function I create a 2D array
crate **Crates = (crate**)malloc(sizeof(crate)*(SCREEN_WIDTH / GrassBlock->w));
for (int i = 0; i <= SCREEN_HEIGHT/GrassBlock->h; i++) {
Crates[i] = (crate*)malloc(sizeof(crate)*(SCREEN_HEIGHT / GrassBlock->h));
}
and I pass it to the function counter = DrawLevelBG(screen, GrassBlock, Border, Crates);. The problem is that the function causes error. "Access violation writing location." at Obstacles[i][j].x = x;
int DrawLevelBG(SDL_Surface *screen, SDL_Surface *sprite, SDL_Surface *border, crate **Obstacles) {
int x = 0;
int y = 0;
int i = 0;
int j = 0;
bool condition = 0;
while (y < SCREEN_HEIGHT + sprite->h) {
DrawSurface(screen, sprite, x + (sprite->w / 2), y + (sprite->h / 2));
if (x >= SCREEN_WIDTH - sprite->w || x == 0 || y == 0 || y >= SCREEN_HEIGHT - sprite->h) {
DrawSurface(screen, border, x + (sprite->w / 2), y + (sprite->h / 2));
Obstacles[i][j].x = x;
Obstacles[i][j].y = y;
Obstacles[i][j].h = border->h;
Obstacles[i][j].w = border->w;
Obstacles[i][j].type = WALL;
i++;
if (x >= SCREEN_WIDTH - sprite->w) {
y += sprite->h;
x = 0;
j++;
condition = 1;
}
}
if (!condition) {
x += sprite->w;
}
condition = 0;
}
return i;
}
I know that these ones are caused by pointers not pointing actually to anything but I can't understand what's wrong here. Any help would be greatly appreciated. Thanks.
EDIT
I've changed my memory allocation piece of code so it looks like that now:
crate **Crates = (crate**)malloc(sizeof(crate*)*(SCREEN_WIDTH / GrassBlock->w)*(SCREEN_HEIGHT / GrassBlock->h));
for (int i = 0; i <= SCREEN_WIDTH/GrassBlock->w; i++) {
Crates[i] = (crate*)malloc(sizeof(crate)*(SCREEN_HEIGHT / GrassBlock->h));
}
According to all your replies guys. Unfortunately this doesnt solve the problem. +Important info, the function DrawLevelBG causes ERROR on the first iteration of loop.

Answer 1

In the first allocation you create an array from pointers. So you need to allocate memory for pointers:
crate **Crates = (crate**)malloc(sizeof(crate*)*(SCREEN_WIDTH / GrassBlock->w));

Answer 2

Thanks for all the help guys. The problem was iterators, not only did I make my 2D array SCREEN_HEIGHT wide and SCREEN_WIDTH high which was the opposite of what I wanted but aswell the iteration in DrawLevelBG was wrong as pointed out. I had to swap my "i" and "j" and make some corrections, so thanks alot Some programmer dude for pointing that out. Thanks alot.