Solve the problem that the Ubuntu 17.10 settings panel cannot be opened

Problem Description##

I don't use the Ubuntu desktop system much. I recently installed Ubuntu 17.10 and used it. I haven't encountered any major problems. The interface style is very similar to Windows, and the overall experience is not bad. Until one day, I suddenly changed the Dock panel from the left to the bottom, and found a new problem: the Settings panel can no longer be opened, as shown in the following figure:

As shown in the figure above, the settings panel is active. You can see the active window when you right-click the mouse, but it just cannot be displayed on the desktop.

solution##

So Google, someone suggested to reinstall gnome-control-center:

sudo apt-get update
sudo apt-get install --reinstall gnome-control-center

But there is no misuse!

Continue to Google, some people have problems like me after uninstalling iBus. Anyway, there are various reasons, but there is no solution! Some people even say that this is a bug in Ubuntu!
So when I asked a colleague who was familiar with Ubuntu, I still didn't solve it. Just when I was about to give up, I saw a problem on a forum that was exactly the same as mine. So I read all the answers with the mentality of a life-saving straw. One of them said that the Dock position can be changed to the default left side by dconf-editor editing parameters. The experiment found that it was successful! The steps are as follows:

sudo apt install dconf-editor
Navigate to org>gnome>shell-extensions>dash-to-dock>dock-position
Restore dock position to it's default value

For details, see: https://bugs.launchpad.net/ubuntu/+source/gnome-control-center/+bug/1721637

In addition, another method is to completely restore the Ubuntu desktop settings, so that the Dock can be restored to the left position, execute the following command:

dconf reset -f /

This is a relatively crude method and will cause all previous desktop settings to be reset, including the desktop background.
For details, please see: https://www.omgubuntu.co.uk/2017/10/how-to-reset-ubuntu-desktop-to-default