I've got a macro in a PowerPoint file that is to export the first slide to a TIF image. It was working before but now has started to give an error. The following is the line of code I use to export the image and it is the line that gives me the error.

Application.ActivePresentation.Slides(1).Export "C:\Users\abc\Desktop\picture.TIF", "TIF"
The error that I get is:

Run-time error '-2147467259 (80004005)':

Slide (unknown member) : Failed.

I've tried searching on Google and can't figure this one out. Any ideas?