i found the issue to be that my local milestone report was corrupted somehow.

I selected any other report that would run, then select "Manage" icon, then select "organiser", then on right hand side, delete "milestone report", then on left hand side select "milestone report", click "copy" in the middle. then you should have restored the standard milestone report.
Close Organiser and try run milestone report and should have data.
hope it works for you.