Question: Problem with the Maple2018 user interface

Hi everybody,

I'm facing that strange and blocking situation:

I was in a Maple 2018 worksheet "W"   (Windows 7, worksheet mode, not document mode) when, probably from some spurious keys combination, the small vertical bar that materializes the position of the mouse disappeared, rendering any further writting impossible.
In the same Maple session I had a few other worksheets  where the this same bar was still present: so it was not a Windows problem (this bar appeared in Word documents too).

I quitted Maple and ran it again. The result is still the same: among all the worksheet I load, only the worksheet  "W"  does not exhibit the location of the mouse.
This problem still persists after rebooting my working station.

Does anyone have any idea to fix this ?

Thanks in advance