Hi.  I am still using Vectorworks 2013.   I haven't upgraded because I don't use it often these days but I do need to be able to open my archived files.  I have it installed on 2 machines.  On one it works fine but on the other it has stopped working.  I can open files but  as soon as I navigate anywhere in the drawing the window goes completely black.  If I try to use a tool there is a floating window which drags and multiplies across the screen.  Sometimes windows flash and resize.  I did a co