I have a PowerPoint 2010 presentation with 523 slides in it. I sent a copy to a colleague, he modified a few slides (added text to them), and sent it back to me. When I use the PowerPoint comparison on my original file and on the file he sent back, nothing happens, where "nothing" means:
After clicking "Merge" (from the Review>Compare dialog), I get the "working" hourglass cursor.
After a while, I see a dialog box with "Press the ESC key to cancel merging the document" in it. After a few seconds, this dialog box disappears.
The cursor returns to normal, and I can navigate around in my document, but there is no pane showing me the differences between the presentations.
I get the same behavior regardless of which of the two pptx files I open first.
Any idea how I can get the PowerPoint comparison feature to work? Or is there another way for me to find the edits my colleague made?