TOPIC: Sites Moved and CSV Export No Longer Works

We moved some 1.0.15 sites runnung DT Register 2.4.6 to a different physical server.

Some can no longer do a csv export from the back end. The menu option still exists. However, when clicked, it does nothing - doesn't display any html.

I am wondering if it is a file permissions problem? Is there anything you can think of that the move might have affected? It worked fine before the move.