Comment 15 for bug 1719482

To rule out a gtk issue you you could try to run the gtk demo:
- download [1]
- copy "gtk-demo.exe" from the /bin directory
  to the Inkscape installation directory
- copy the share/ folder to the Inkscape installation directory
- execute "gtk-demo.exe" from cmd.exe

(you can play around a bit with it and have an eye on the command line output - maybe something suspicious comes up)

[1] http://repo.msys2.org/mingw/x86_64/mingw-w64-x86_64-gtk2-2.24.31-4-any.pkg.tar.xz