Export Chart As Image

I have used this code for over a year now and for some reason when i transfer it to a new workbook I am now getting a Run Error 91.

Code:

'Take ActiveChart and copy it as a GIF image to the same directory as the Workbook is in and name it with the Chart_Title with spaces replaced with underscores.

Dim chtCopyChart As Chart, sCurrentDirectory As String, sFileName As String Dim x As Integer, CellCharacter As String
Set chtCopyChart = ActiveChart
sCurrentDirectory = ActiveWorkbook.Path

[Code]...

The code is breaking on this line

Code:

chtCopyChart.Export Filename:=sFileName, FilterName:="GIF"

It almost seems to me like the code is not selecting the activechart, but, not entirely sure.