BUG: Error 405: "Unable to Show Modal Form Within this Context"

• Microsoft Visual Basic Learning, Professional, and Enterprise Editions for Windows, versions 5.0, 6.0

SYMPTOMS

When opening a form from an ActiveX DLL, you may receive the following error:

Unable to show modal form within this context."

CAUSE

This error occurs when all of the following are true:

• The computer is running Windows 95 or Windows 98.



• The ActiveX DLL has been compiled.



• The client application is in the Visual Basic IDE.



• The client application form has a BorderStyle property set to Dialog.



• The ActiveX DLL form has been previously opened.

RESOLUTION

Set the BorderStyle of the form in the client application to Fixed Single, and remove the Min and Max buttons from the form. This results in the form behaving in the same manner as a form with a Dialog BorderStyle.

STATUS

Microsoft has confirmed this to be a bug in the Microsoft products listed at the beginning of this article. We are researching this bug and will post new information here in the Microsoft Knowledge Base as it becomes available.

MORE INFORMATION

Steps to Reproduce Behavior

1. Create an ActiveX DLL in Visual Basic. Name the project "SrvDialog." Place the following code in Class1:

   
          Option Explicit
          Public Sub ShowDialog()
              Form2.Show 1
          End Sub
    




2. Add a form to the project. Change the Name and Caption properties to "Form2." Place the following code on Form2:

   
          Option Explicit
          Private Sub Form_Click()
              Unload Me
          End Sub
    




3. Compile the DLL.



4. Create a Standard EXE project in Visual Basic. Form1 is created by default. Make a reference to SrvDialog.DLL.



5. Change the BorderStyle property of Form1 to 3 (Fixed Dialog). Place a CommandButton on Form1, and place the following code on Form1:

   
          Option Explicit
          Private Sub Command1_Click()
          Dim x As New SrvDialog.Class1
             x.ShowDialog
             Set x = Nothing
          End Sub
    




6. Run the client application. Click Command1.



7. Click Form2 to unload that form.



8. Click Command1 again and note that Error 405 occurs.

Additional query words: kbVBp500bug kbVBp kbDSupport kbdsd kbForms kbVBp600bug kbDLL kbActiveX
kbServer

Keywords : kbGrpVB
Version :
Platform : WINDOWS
Issue type : kbbug