It may be that the parameters window is rendering off-screen. This phenomenon can be caused by using a second monitor and subsequently removing it.
Select one of the reports in question.
Call up the parameters window.
At this point, use key-combo ALT-SPACEBAR (a small context menu may or may not appear at the edge of the monitor)
Tap the letter M on your keyboard to invoke the 'Move' command.
Use your keyboard's ARROW keys. (likely the LEFT ARROW key) to hopefully move the orphaned window back on-screen.