I am using Lubuntu 17.10 and every time I start the computer, after Lubuntu boots it shows this error:
WARNING: Failed to connect to lvmetad. Falling back to device scanning.
/dev/mapper/lubuntu--vg-root: clean, 239554/9674752 files, 19597960/38680576 blocks
When I turn off the computer the same error appears and after that it shows a blue screen and gets stuck in this position (doesn't turn off).
