Is there any way to resolve Null pointer reference. My Client Exits with error code 0xc0000005

I'm trying to reproduce a defect in my client application. But it got hanged before reproducing the defect with Exception code 0xC0000005 . I need to open multiple image to reproduce defect. But in the half way application got hang(No memory issue).

I Created a dump file analyzed the same So the information I found is "A Thread is trying to read from or write to a virtual address for which it does not have the appropriate access." The particular Client code is working with other machine. I have verified there is no memory issue.

Indicator()
{
    A* p = create(Arguments);
    ASSERT(p);
    //new images Arrived
    p = create(updated arguments);
    ASSERT(p);

    // Remote Study 
    p = create(updated Arguments);
    ASSERT(p);
    ..
    ..
    ..
    ..
    m_var = p->GetSize(); //read access violation,(retured 0x130)
                         //p is getting null pointer.
} 

My client claims there is no error in code . I expect That The client should work successfully with out error code(0xC000005) as it is working fine in other machine. in Application, Some the images are getting loaded successfully but after few successful loads, while attempting to open next image my code hangs at the given line of code. I got the code from the dump file.