C++ simple object destruction error

Question

I have written a code which contains a const variable in its class declaration. However I initialize the value of the variable in a function of the class. And I can use that variable without any pain throughout that class. But when I try to access that variable via another function of the class I cannot . It seems its value is set to NULL . Here is the declaration of the class (the variable part only)

public:
    const aiScene *pScene;

And I am initializing it in a function named LoadModel()

pScene = imp.ReadFile(fileName,
    aiProcess_CalcTangentSpace |
    aiProcess_ConvertToLeftHanded |
    aiProcess_Triangulate |
    aiProcess_GenSmoothNormals |
    aiProcess_OptimizeMeshes);

if (pScene == NULL)
    MessageBoxA(NULL, imp.GetErrorString(), "Error", MB_OK);

If I call a function called Update() in this LoadModel() function which uses this variable it works perfectly but when I call it in Render() function of the same class the program crashes. I can see in the debugger that the pScene has some error "Unable to read memory"

Answer 1

Made the variable "imp" global. Silly mistake....