I have the same issue of dragging items in the display port and the same problem is present when you try to drag n drop items in the screen library tree on the right side of the screen.
I have also an issue with the Plus+1 Update Center, the software start then froze on a white window.....Plus+1 Update Center not responding message show up if I try to click anywhere in the window.
Plus+1 version 12.0.7.29
I think the problem begin after the installation of that file « PLUS+1 Base 1.0.95 setup.exe » by the update center software.
If this can help find a fix.
Regards