DOCUMENT:Q221743 27-JUL-1999 [foxpro] TITLE :FIX: NVL() Releases Object Ref and Causes Fatal Error C0000005 PRODUCT :Microsoft FoxPro PROD/VER:WINDOWS:5.0,5.0a,6.0 OPER/SYS: KEYWORDS:kberrmsg kbservicepack kbOOP kbvfp500aBUG kbvfp600 kbvfp600bug kbVS600sp2 kbVS600SP1 kb ====================================================================== ------------------------------------------------------------------------------- The information in this article applies to: - Microsoft Visual FoxPro for Windows, versions 5.0, 5.0a, 6.0 ------------------------------------------------------------------------------- SYMPTOMS ======== Calling the NVL() function multiple times in Visual FoxPro 5.0 causes the following error message: Property is not method or event. If you click the Ignore button in the error dialog box and run the program again, you normally see the following error: An application error has occurred and an application log is being generated. VFP.exe Exception: access violation (0x0000005), Address: In some instances, the first error message is skipped and the second error is displayed. The following error can also occur: The instruction at "0x00401e44" referenced memory at "0x010bb018". The memory could not be "read". In Visual FoxPro 6.0, the following error often appears after calling the NVAL() function the third time: Fatal error: Exception code: C0000005 CAUSE ===== The NVL() function saved the handle, but it released the object reference. STATUS ====== Microsoft has confirmed this to be a bug in the Microsoft products listed at the beginning of this article. This bug was corrected in Visual Studio 6.0 Service Pack 3. For more information about Visual Studio service packs, please see the following articles in the Microsoft Knowledge Base: Q194022 INFO: Visual Studio 6.0 Service Packs, What, Where, Why Q194295 HOWTO: Tell That Visual Studio 6.0 Service Packs Are Installed MORE INFORMATION ================ Steps to Reproduce Behavior --------------------------- 1. Create a program that contains the following code: ox = CreateObject("Lbltest") ox.Test() ox.Test() ox.Test() Define Class Lbltest as Label Procedure Test oObj = NVL(.NULL.,This) ?oObj.name EndProc Enddefine 2. Run the program. After accessing the Test procedure the third time, one of the errors listed in the SYMPTOMS section above appears. Additional query words: ====================================================================== Keywords : kberrmsg kbservicepack kbOOP kbvfp500aBUG kbvfp600 kbvfp600bug kbVS600sp2 kbVS600SP1 kbVS600sp3fix kbGrpDSFox Technology : kbVFPsearch kbAudDeveloper kbVFP500 kbVFP600 kbVFP500a Version : WINDOWS:5.0,5.0a,6.0 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 1999.