Order of events reversed 'Ribbon_Load' and 'ThisAddin_Startup' Word VSTO Add-in. (Build 8201.2025 onwards)

As of Build 8201.2025 there has been an unexpected change to the order of events when loading a VSTO addin with a Ribbon in Word.

• Using Office version 16.0.8067.2115 or older. When loading the addin the following order of events is observed (as has always been the case).

Ribbon_Load event

ThisAddin_Startup event

• Using Office versions 8201.2025, 8201.2064 or 8201.2075 or newer the order of events is reversed which is an unexpected breaking change.

ThisAddin_Startup event

Ribbon_Load event

• I have created a simple VSTO Addin using a Visual Designer Ribbon to demonstrate the issue.

>

Public Class Ribbon1
    Private Sub Ribbon1_Load(ByVal sender As System.Object, ByVal e As RibbonUIEventArgs) Handles MyBase.Load

        System.Diagnostics.Debug.Write("Ribbon1_Load event called.")

        'Pass the Ribbon to the Addin.

        ThisAddIn.MyRibbon = Me

    End Sub
End Class

Public Class ThisAddIn

Public Shared Property MyRibbon As Ribbon1 = Nothing

    Private Sub ThisAddIn_Startup() Handles Me.Startup
        Debug.Write("ThisAddin_Startup Called")

        If (MyRibbon Is Nothing) Then
            Debug.Write("MyRibbon is nothing - the ribbon was not captured.")
        Else
            Debug.Write("Ribbon captured successfully.")
        End If

    End Sub
End Class

• Debug output for 16.0.8067.2115 32 bit

  • [7772] Ribbon1_Load event called.

  • [7772] ThisAddin_Startup Called

  • [7772] Ribbon captured successfully.

• Debug output for 16.0.8201.2075 32 bit

  • [13556] ThisAddin_Startup Called
  • [13556] MyRibbon is nothing - the ribbon was not captured.
  • [13556] Ribbon1_Load event called

I have posted this up on the Microsoft Support forums however they have stopped responding and since released this version to the Current office channel I need help from the dev community.

Has anyone found a successful workaround? This change of timing is causing alot of problems with how we initialise. It would be ideal for Microsoft Support to provide a solution or workaround until they investigate this bug.

Hope this helps someone! We used the following workaround successfully to work around the changed office load behavior.

Within ThisAddIn_Startup loop until the Ribbon load event has fired and the ribbon is captured.

 While m_oRibbon Is Nothing
        If (timeWaited >= MAX_WAIT_TIME) Then
            Exit Try
        End If

        Threading.Thread.Sleep(50)
        timeWaited = timeWaited + 50
 End While