O Xubuntu (XFCE) não é iniciado corretamente ao usar a Intel Graphics

Question

desde ontem meu sistema não funciona corretamente. Se eu usar meu segundo monitor controlado por um driver gráfico da Intel, não posso começar a minha área de trabalho e ser sempre devolvido à tela de login. Se eu desligar o segundo monitor, há três mensagens de erro que dizem: "Há um problema com uma aplicação sistemática". Últimas atualizações que eu instalei:

tart-Date: 2018-02-12 20:28:03 Commandline: apt-get upgrade -y Requested-By: dominik (1000) Upgrade: update-manager-core:amd64 (1:16.04.10, 1:16.04.12), update-manager:amd64 (1:16.04.10, 1:16.04.12), xserver-xorg-video-amdgpu-hwe-16.04:amd64 (1.3.0-0ubuntu1~16.04.1, 1.4.0-1~16.04$ End-Date: 2018-02-12 20:28:12

cat /home/dominik/.local/share/xorg/Xorg.2.log | grep EE:

WW) warning, (EE) error, (NI) not implemented, (??) unknown.
[   101.185] (EE) open /dev/fb0: Permission denied
[   102.551] (EE) 
[   102.551] (EE) Backtrace:
[   102.551] (EE) 0: /usr/lib/xorg/Xorg (xorg_backtrace+0x4e) [0x55d5ce21ee1e]
[   102.551] (EE) 1: /usr/lib/xorg/Xorg (0x55d5ce06d000+0x1b5b89) [0x55d5ce222b89]
[   102.551] (EE) 2: /lib/x86_64-linux-gnu/libpthread.so.0 (0x7fdf368e1000+0x11390) [0x7fdf368f2390]
[   102.551] (EE) 3: /usr/lib/xorg/modules/drivers/radeon_drv.so (0x7fdf32a19000+0x49037) [0x7fdf32a62037]
[   102.551] (EE) 4: /usr/lib/xorg/modules/drivers/radeon_drv.so (0x7fdf32a19000+0x49653) [0x7fdf32a62653]
[   102.551] (EE) 5: /usr/lib/xorg/modules/drivers/radeon_drv.so (0x7fdf32a19000+0x4b0d8) [0x7fdf32a640d8]
[   102.551] (EE) 6: /usr/lib/xorg/Xorg (BlockHandler+0xcf) [0x55d5ce0c5def]
[   102.551] (EE) 7: /usr/lib/xorg/Xorg (WaitForSomething+0x93) [0x55d5ce21c6c3]
[   102.551] (EE) 8: /usr/lib/xorg/Xorg (0x55d5ce06d000+0x540c1) [0x55d5ce0c10c1]
[   102.551] (EE) 9: /usr/lib/xorg/Xorg (0x55d5ce06d000+0x583b8) [0x55d5ce0c53b8]
[   102.552] (EE) 10: /lib/x86_64-linux-gnu/libc.so.6 (__libc_start_main+0xf0) [0x7fdf36537830]
[   102.552] (EE) 11: /usr/lib/xorg/Xorg (_start+0x29) [0x55d5ce0af329]
[   102.552] (EE) 
[   102.552] (EE) Segmentation fault at address 0x49
[   102.552] (EE) 
[   102.552] (EE) Caught signal 11 (Segmentation fault). Server aborting
[   102.552] (EE) 
[   102.552] (EE) 
[   102.552] (EE) Please also check the log file at "/home/dominik/.local/share/xorg/Xorg.2.log" for additional information.
[   102.552] (EE) 
[   102.570] (EE) Server terminated with error (1). Closing log file.

lshw -C video

Beschreibung: VGA compatible controller
       Produkt: Cape Verde XT [Radeon HD 7770/8760 / R7 250X]
       Hersteller: Advanced Micro Devices, Inc. [AMD/ATI]
       Physische ID: 0
       Bus-Informationen: pci@0000:01:00.0
       Version: 00
       Breite: 64 bits
       Takt: 33MHz
       Fähigkeiten: pm pciexpress msi vga_controller bus_master cap_list rom
       Konfiguration: driver=radeon latency=0
       Ressourcen: irq:30 memory:e0000000-efffffff memory:f7d00000-f7d3ffff ioport:e000(Größe=256) memory:c0000-dffff
  *-display
       Beschreibung: Display controller
       Produkt: Xeon E3-1200 v3/4th Gen Core Processor Integrated Graphics Controller
       Hersteller: Intel Corporation
       Physische ID: 2
       Bus-Informationen: pci@0000:00:02.0
       Version: 06
       Breite: 64 bits
       Takt: 33MHz
       Fähigkeiten: msi pm bus_master cap_list
       Konfiguration: driver=i915 latency=0
       Ressourcen: irq:29 memory:f7800000-f7bfffff memory:d0000000-dfffffff ioport:f000(Größe=64)

Por algum motivo, o vídeo lshw -C reconhece a unidade de gráficos da Intel.

Espero que você possa me ajudar.

Atenciosamente

Dominik