I’ve been having the same problem, it does seem to be an issue with one of my monitors (I have 3, all 1920x1080). Slic3r 1.3.0, windows 10.
On my main monitor, everything works fine. If the window opens on the right monitor I get “Not Responding”. Haven’t tried the left one, thats my netflix monitor 
I’ve been using slic3r for a long time, but this issue seems new to me. I will disable saving/restoring of window position for now, but hopefully it can get resolved at some point.