FIX: CLEAR ALL with Object References Causes Page Fault

ID: Q158755

The information in this article applies to:
  • Microsoft Visual FoxPro for Windows, version 5.0

SYMPTOMS

If there are objects that reference each other, Visual FoxPro displays the following error message when CLEAR ALL is carried out:

This Program has performed an illegal operation and will be shut down.
Visual FoxPro terminates due to an Invalid Page Fault.


WORKAROUND

Delete object references before carrying out CLEAR ALL.


STATUS

Microsoft has confirmed this to be a problem in the Microsoft products listed at the beginning of this article. This has been corrected in Visual FoxPro 6.0.


MORE INFORMATION

Steps to Reproduce Behavior

  1. Create and run a program containing the following code: 
    
      oform = CreateObject( "Form" )
      oform.AddObject("X", "CB")
      oform.AddObject("Y", "CB")
      oform.y.pointer=oform.x
      oform.x.pointer=oform.y
      CLEAR ALL  && This causes an Invalid Page Fault and
                 && shuts down Visual FoxPro.

      DEFINE CLASS CB as CommandButton
        pointer= .NULL.
      ENDDEFINE


Object references for "X" and "Y" above can be cleared by doing the following: 

      oform.removeobject("X")
      oform.removeobject("Y")

Additional query words: vfoxwin kbdsd kbvfp500 kbvfp600fix

Keywords : kberrmsg FxenvError FxprgClassoop
Version : WINDOWS:5.0
Platform : WINDOWS
Issue type :


Last Reviewed: August 12, 1999
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