Runtime Error 1004, code previously worked fine

[Eatmybrain]

Hi

Apologies if this has been asked elsewhere.

I have the following code:

Sub SendMorningEmails()

    With Application
        .EnableEvents = False
    End With
    
    Dim TempFilePath As String
    
    Set appOutlook = CreateObject("outlook.application")
    
    Set Message = appOutlook.CreateItem(olMailItem)
    
    With Message
        .Subject = "Reservation Volumes"
        .HTMLbody = "<p style=font-family:calibri;font-size:14.5>" & "Dear All" & "<br>" & "<br>"
            
'This section creates an image as a PNG file to embed in the body of the email, the type of image can be altered by changing this designation, ie, to .jpg in the code below
    
    ThisWorkbook.Activate
    Sheet31.Visible = True
    Sheet31.Activate
    Set Plage = Sheet31.Range("F62:O127")
    Plage.CopyPicture
    
    With ThisWorkbook.Worksheets("Morning Emails").ChartObjects.Add(Plage.Left, Plage.Top, Plage.Width, Plage.Height)
        .Activate
        .Chart.Paste
        .Chart.Export Environ$("temp") & "\" & "MEmailFile" & ".png", "PNG"
    End With
    
    Sheet31.ChartObjects(Sheet31.ChartObjects.Count).Delete
    
    Set Plage = Nothing
    
'This section attaches the embedded image with a Position at 0 to makes the attachment hidden
    
    TempFilePath = Environ$("temp") & "\"
        .Attachments.Add TempFilePath & "MEmailFile.png", olByValue, 0
        
'This section adds an html <img src=''> link to this image
'Using the "<br>" fucntion and the text within the speech marks this section adds the signature to the email
    
    .HTMLbody = .HTMLbody _
        & "<img src='cid:MEmailFile.png'" _
        & "<br>" & "Kind regards" _
        & "<br>" & "<br>" & "<B>Rich Thornton</B>" _
        & "<br>" & "Marketing Executive - Mortgages" _
        & "<br>" & "<br>" & "01793 653009" & "<br>" & "<br>" _
        & "<B><font-family:calibri;font-size:14.5><font color=red>Please treat this e-mail and any accompanying documentation as confidential.</font></B>" & "</p>"
        
        .To = Sheet33.Cells(5, 2)
        .Cc = ""
        .Display
    End With
    
    With Application
        .EnableEvents = True
    End With
        
End Sub

Which until today worked fine, however when it runs it brings up a runtime 1004 error at the highlighted line. I've tried all I know but can't get it to work. As mentioned is worked fine until today which is odd I feel!

Thanks in advance

[Eatmybrain]

In fact the code works fine in another (older) workbook, but doesn't in the new one.