Upgrade the kernel (4.11.0-1-amd64 -> 4.12.0-1-amd64) and run "xhost +si:localuser:root", synaptic works again (must run the xhost on each login).
- Bug#872553: synaptic: Segmentation fault zaoqi
- Bug#872553: synaptic: Segmentation fault Schmidt Cristian Hernan
- Bug#872553: More information Cristian Hernán Schmidt