error c0000374, has triggered a breakpoint

In the function, in the middle of 'while' loop (not in the first loop), I get an error: 'has triggered a breakpoint.' in another computer the error does not appear.

'product' is a struct I created the error is in line 'temp = (product*)malloc(sizeof(product));' when I press continue the next error appears: 'Unhandled exception at 0x777C8529 (ntdll.dll) in ConsoleApplication39.exe: 0xC0000374: A heap has been corrupted (parameters: 0x778058A0).'

this is the code of the function:

product* CreateProducts(product *head, FILE* out)
{
    char tempname[100];
    FILE* in = fopen("Manot.txt", "r");
    if (in == NULL)
        GetLost("can't open the file");
    product *temp;
    temp = (product*)malloc(sizeof(product));
    if (temp == NULL)
    {
        freelist(head);
        GetLost("error! not enough memory");
    }

    while (fscanf(in, "%s%d%d %c", tempname, &(temp->quantity), &(temp->price), &(temp->primium)) != EOF)
    {
        temp->next = head;
        head = temp;
        if (head->quantity < 0 || head->price<0)
            fprintf(out, "quantity and price should be positive\n");
        else {
            head->productname = (char*)malloc(sizeof(strlen(tempname) + 1));
            if (head->productname == NULL)
            {
                freelist(head);
                GetLost("error! not enough memory");
            }
            strcpy(head->productname, tempname);
            temp = (product*)malloc(sizeof(product));
            if (temp == NULL)
            {
                freelist(head);
                GetLost("error! not enough memory");
            }

        }
    }

    fprintf(out, "the kitchen was created\n");
    return head;
}