Userform "Invalid property value" Error When Unloaded

[Ark68]

I have a form in my project. Very simple, one combobox. The user simply enters a value of 1-6. ENtering a valid value in the combobox closes the userform and code continues based on the information provided by the user.
When the user form closes, I am getting an error. Mircrosoft Forms Error: "Invalid property value"

Suppose I select "1" from the combox. It goes to routine "pop_Dsvc". I unload the userform at the top of this procedure with "Unload frm_select". No negative consequences resul in the rest of the application following this error to my knowledge. It just simply breaks the flow.

Here is the code associated with my form:

Private Sub ComboBox1_Change()
'Stop
    If Not mbevents Then Exit Sub
    ui1 = ComboBox1.Value
    If ui1 = "1" Then
        pop_Dsvc 'svcnum
    ElseIf ui1 = "2" Then
        pop_Fsvc 'svcnum
    ElseIf ui1 = "3" Then
        pop_Csvc 'svcnum
    ElseIf ui1 = "4" Then
        pop_Tsvc 'svcnum
    ElseIf ui1 = "5" Then
        pop_Psvc 'svcnum
    ElseIf ui1 = "6" Then
        selectAll
    ElseIf ui1 = "7" Then
        'Stop
        With ws_front
            Unload frm_select
            .Shapes("ins_crewpkgs_output").Visible = True
            .Shapes("ins_crewpkgs_output").OnAction = "crewpkgs1"
            .Shapes("oos_crewpkgs_output").Visible = False
        End With
    Else
        mbevents = False
        combox1.Value = "6"
        mbevents = True
    End If
End Sub


Private Sub UserForm_Initialize()
    mbevents = False
    ComboBox1.Value = ""
    mbevents = True
End Sub

 

[Ark68]

Solved.
Match Required property was set to true. Changed to false and no error. Don't really understand why, but it worked.