DOCUMENT:Q177703 27-JAN-2001 [vbwin] TITLE :FIX: Access Violation with Public Enums in UserControl PRODUCT :Microsoft Visual Basic for Windows PROD/VER::5.0 OPER/SYS: KEYWORDS:kbCtrlCreate kbVBp kbVBp500bug kbVBp600fix kbVS97sp2 kbGrpDSVB kbDSupport kbControl ====================================================================== ------------------------------------------------------------------------------- The information in this article applies to: - Microsoft Visual Basic Professional Edition for Windows, version 5.0 - Microsoft Visual Basic Enterprise Edition for Windows, version 5.0 ------------------------------------------------------------------------------- SYMPTOMS ======== When exiting a Visual Basic 5.0 ActiveX Control project in the design environment, an Access Violation error occurs and Visual Basic is terminated. CAUSE ===== This problem can occur when declaring Public Enum in the UserControl module when running Visual Studio 97 Service Pack 2 (SP2.) RESOLUTION ========== Move the Public Enums to a standard (.bas) module instead of the UserControl module. STATUS ====== Microsoft has confirmed this to be a bug in the Microsoft products listed at the beginning of this article. This bug has been fixed in Visual Basic 6.0. MORE INFORMATION ================ Steps to Reproduce Behavior --------------------------- NOTE: To reproduce the problem, you must have Visual Studio 97 Service Pack 2 installed. 1. Create a new ActiveX control project. 2. Add another UserControl to the project so you have UserControl1 and UserControl2. 3. Place UserControl2 inside UserControl1. 4. Add the following code to UserControl1: Option Explicit Public Enum BorderStyle_Type None = 1 FixedSingle = 2 End Enum Public Enum Appearance_Type Flat = 1 ThreeDimensional = 2 End Enum 5. Close the design windows of UserControl1 and UserControl2. 6. Add a Standard EXE project so that you have a project group. Form1 is created by default. 7. Add UserControl1 to Form1. 8. Optional: Save the project group. 9. Exit Visual Basic to close the project group. In Windows 2000, you receive the following error: The instruction at "0x0fb20cc8" referenced memory at "0x00000010". The memory could not be read. In Windows NT 4.0, Service Pack 3 you receive the following error: Access Violation in VB5.exe at 0x0fb25f69 In Windows 95, Windows 98, or Windows Me, you receive the following error: VB5 caused an invalid page fault in module VBA5.DLL Additional query words: IPF GPF crash ====================================================================== Keywords : kbCtrlCreate kbVBp kbVBp500bug kbVBp600fix kbVS97sp2 kbGrpDSVB kbDSupport kbControl Technology : kbVBSearch kbAudDeveloper kbZNotKeyword6 kbZNotKeyword2 kbVB500Search kbVBA500 kbVB500 Version : :5.0 Issue type : kbbug Solution Type : kbfix ============================================================================= THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. MICROSOFT DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL, CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES SO THE FOREGOING LIMITATION MAY NOT APPLY. Copyright Microsoft Corporation 2001.