My mouse and keyboard use the same dongle to connect to the system. That mouse and keyboard works correctly on other systems. I have checked another mouse and keyboard to connect to my system. The result is the same. The Ubuntu 18.04.5 doesn't recognized them. Currently I can connect to system through ssh.
Some part of the output of the below command is:
cat /var/log/syslog | grep device
boltd[6544]: store: loading devices
boltd[6544]: udev: enumerating devices
kernel: [ 78.088098] logitech-hidpp-device 0003:046D:4016.0005: HID++ 2.0 device connected.
upowerd[6324]: treating change event as add on /sys/devices/pci0000:00/0000:00:14.0/usb3/3-4/3-4:1.2/0003:046D:C52B.0003/0003:046D:4016.0005/power_supply/hidpp_battery_1
dev-sdb1.device: Job dev-sdb1.device/start timed out.
Timed out waiting for device dev-sdb1.device.
dev-sdb1.device: Job dev-sdb1.device/start failed with result 'timeout'.
Starting Virtual filesystem service - disk device monitor...
Started Virtual filesystem service - disk device monitor.
dev-sdb1.device: Job dev-sdb1.device/start timed out.
Timed out waiting for device dev-sdb1.device.
dev-sdb1.device: Job dev-sdb1.device/start failed with result 'timeout'.
dev-sdb1.device: Job dev-sdb1.device/start timed out.
Timed out waiting for device dev-sdb1.device.
dev-sdb1.device: Job dev-sdb1.device/start failed with result 'timeout'.
What should I do to come back my system functionality?
if you want any other information let me know.
I found that I have uninstalled
xserver-xorg-input-allpreviously. The main reason of problem is there is no input driver so it couldn't be mounted as a valid device. So the problem simply can be solved by executing this: