For original problem with Ubuntu MATE Welcome one can use crash file from this link - https://bugs.launchpad.net/ubuntu/+source/xorg-server/+bug/1796437/+attachment/5319138/+files/_usr_lib_xorg_Xorg.0.crash .
For original problem with Ubuntu MATE Welcome one can use crash file from this link - https:/ /bugs.launchpad .net/ubuntu/ +source/ xorg-server/ +bug/1796437/ +attachment/ 5319138/ +files/ _usr_lib_ xorg_Xorg. 0.crash .