Chart exporting error

[sdoppke]

Hi there folks, hoping to get some help with a strange error. I use the below code to export charts as pics. The below code works great but will only do so on 3 of the 7 charts always works for the first 3 then error saving the picture (actually no error saving just save as 0kb empty or corrupt file). When I go to the page with the charts and click into them all one by one (activate them) then works fine.

thanks for any help.

Private Sub UpdateChart()
    Application.ScreenUpdating = False
    Set CurrentChart = Sheets("Schedule Tool1").ChartObjects(ChartNum).Chart
'   Save chart as GIF
    'Fname = ThisWorkbook.Path & Application.PathSeparator & "Chart.tif"
    Fname = "C:\WINDOWS\Temp" & "Chart.gif"
    CurrentChart.Export Filename:=Fname, FilterName:="GIF"
    Application.ScreenUpdating = False
    
'   Show the chart
    Image1.PictureSizeMode = 1
    On Error Resume Next
    Image1.Picture = LoadPicture(Fname)
End Sub