Hi , This is what I have done. I was just trying a project, which involves creating a simple add-in using the SolidWorks Addin App Wizard. I have SolidWorks 2001 Plus and VC++ Version 6.0. I created a simple application using the default settings in the App Wizard. Then changed to configuration to Win32 MBCS Debug/Release and built the application. It worked fine. Then I created a new dialog resource. I created a new dialog class for the resource. Then wrote code for the DoModal method as mentioned in the tutorial. This is the code that I wrote: HINSTANCE hInst = AfxGetResourceHandle(); if (m_lpszTemplateName != NULL) { TheApplication->SetResources(); hInst = AfxFindResourceHandle(m_lpszTemplateName,RT_DIALOG); HRSRC hResource = ::FindResource(hInst,m_lpszTemplateName,RT_DIALOG); m_hDialogTemplate = LoadResource(hInst,hResource); TheApplication->ResetResources(); } Then I added the necessary headerfiles in the relevant places. Added amapp.h,ExampleApp.h and resource.h to the Dialog.cpp header file. and added dialog.h file to mainapp.cpp file. I invoked the DialogBox from the MenuItemCB function. The code looks like this: void MenuItemCB(void) { CSettingsDlg dlg; dlg.DoModal(); return; } Now, when I try to build the application, it build fine. I launch the dll inside SolidWorks, and when I open the dialog box by clicking on the menu button, it opens up, but hangs the SolidWorks Application and it eventually crashes saying that it encountered an unhandled error. Is there anything that I am missing over here?? Please help me out. Thanks, Sushil.