This only started happening recently. No matter which original drawing I open, for some reason scroll-zooming is extremely slow and laggy. Also, when I select multiple object with the select window by just clicking the screen and highlighting what I want, then type a "move" command to move these objects, the software is crashing. At first it was just the scroll zooming which was a nuisance but usable. Now I can't even work on a drawing that I made myself in Draftsight only a few months ago. This happens with any drawing, by the way. And the same drawings work fine on other computers. I think this started when I upgraded to 2015 SP3, but I am not sure.