MFC error: Debug assertion failed c++ VIEWSCRL.CPP

void CMainFrame::OnViev() 
{
    if(view==0)return;
    view=0;
    CView*p_view_vrem = GetActiveView();
    CInstView* pp = new CInstView;
    pp->Create (NULL,NULL,AFX_WS_DEFAULT_VIEW,rectDefault,this,AFX_IDW_PANE_FIRST,NULL);
    GetActiveDocument()->AddView (pp);
    GetActiveView()->ShowWindow (SW_HIDE);
    GetActiveDocument()->RemoveView(GetActiveView());
    SetActiveView(pp);
    delete p_view_vrem;
    RecalcLayout();
}
 
 
void CMainFrame::OnViev1() 
{
    if(view==1)return;
    view=1;
    CView*p_view_vrem = GetActiveView();
    CInstViev1* pp = new CInstViev1;
    pp->Create (NULL,NULL,AFX_WS_DEFAULT_VIEW,rectDefault,this,AFX_IDW_PANE_FIRST,NULL);
    GetActiveDocument()->AddView (pp);
    GetActiveView()->ShowWindow (SW_HIDE);
    GetActiveDocument()->RemoveView(GetActiveView());
    SetActiveView(pp);
    delete p_view_vrem;
    RecalcLayout();
}

// CScrollView painting
void CScrollView::OnPrepareDC(CDC* pDC, CPrintInfo* pInfo)
{
    ASSERT_VALID(pDC);
 
#ifdef _DEBUG
    if (m_nMapMode == MM_NONE)
    {
        TRACE0("Error: must call SetScrollSizes() or SetScaleToFitSize()");
        TRACE0("\tbefore painting scroll view.\n");
        ASSERT(FALSE);
        return;