Why does the function scan_for doesn't work? Open hash linear probing

I have a problem with implementing open addressing hash table that uses linear probing. I suspect that the problem is with the function called scan_for. Code::Blocks returns -10737741819 (0xC0000005).

const int table_size = 10;

class HashTable
{
public:
   int key;
   int value;
   HashTable(int key, int value)
   {
     this->key = key;
    this->value = value;
   }
 };

class DelNode:public HashTable
{
private:
static DelNode *en;
DelNode():HashTable(-1,-1){}
public:
static DelNode *getNode()
{
    if (en==NULL)
    {
        en = new DelNode();
    }
        return en;
    }
};
DelNode *DelNode::en = NULL;

class HashMapTable
{
private:
HashTable **ht;
public:
HashMapleTable()
{
    ht = new HashTable* [table_size];
    for (int i=0; i<table_size; i++)
    {
        ht[i] = NULL;
    }
}

int HashFunction(int k)
{
    return k%table_size;
}

int scan_for(int k)
{
    int index = k%table_size;
    int deleted = -1;
    int i = index;

    while (ht[i]!=NULL)
    {
        if (ht[i]==DelNode::getNode())
        {
            if (deleted==-1) deleted = i;
        }
        else if (ht[i]->value==k) return i;
        i = (i+1)%table_size;
        if (i==index) return deleted;
    }
    if (deleted!=-1) return deleted;
    return i;
}

void insert(int x)
{
    int i = scan_for(x);
    if (i!=-1) ht[i] = new HashTable(i,x);
}

void remove(int x)
{
    int i = scan_for(x);
    if (i!=-1)
    {
        delete ht[i];
        ht[i] = DelNode::getNode();
    }
}

~HashMapTable()
{
    delete[] ht;
}

Ht is hash table that contains keys and values. Function scan_for is a helper function that is used in function such as insert, remove, delete. It searches correct key using linear probing and returnes it, or -1 if it is deleted.