Use midi Draw ,cubase stuck. Please help!!!

Hello, everyone, I have a problem with the use of Cubase, please help.

Once the MIDI edit window with a Draw, and mobile mouse, the entire Cubase stuck, the cursor, the time schedule, will not move, do not move the mouse normal.
In the Cubase preferences inside Edit - tools - cross cursor, the display of vertical lines, and show the horizontal line are all points. Resume normal.

But in the multi track interface, there is no vertical line, especially in the non quantitative shear, which is very difficult.

Although this is not MIDI editing interface with the Draw Get stuck screen, but Cubase still has the whole Get stuck , when a mouse click to enter notes, there are intermittent feeling. In the multi track editing interface, zoom and move the clip is very not smooth.

Version 8 8.5 have tried the problem is still,
system win10 win 7 win have tried the problem is still.