Seem to be into a "rough patch" with U-MATE lately . . . again running apt dist-upgrade in GUI console causes crashing of GUI.
Bug report filed . . . don't know if this relates to the "Xorg crash" thread in 20.04 . . . . https://bugs.launchpad.net/ubuntu/+source/ubuntu-release-upgrader/+bug/1892522
Running a standard "apt dist-upgrade" in U-MATE 20.10 via GUI console & part way through suddenly the screen flashes black and a brief TTY-like dmesg data shows "[Failed] and a bunch of data before going black again . . . . Seems like the GUI was crashed . . . . After a minute the mouse cursor came back and then the log-in window.
I logged in and saw the "error" applet up on the toolbar . . . saying "possibly unmet dependencies" . . . launched the console again and it said, "dpkg was interrupted, run 'sudo dpkg --configure -a'" . . . so I ran that, and a few errors on "libreoffice" showed up . . . it was running through the items again . . . and then the same crash of the GUI happened again . . . ???