It sounds like the XFCE window manager has crashed, but I'm not sure. It might be a good idea to follow these steps:
https://wiki.ubuntu.com/Bugs/Responses#Missing_a_crash_report_or_having_a_.crash_attachment
It sounds like the XFCE window manager has crashed, but I'm not sure. It might be a good idea to follow these steps:
https:/ /wiki.ubuntu. com/Bugs/ Responses# Missing_ a_crash_ report_ or_having_ a_.crash_ attachment