Why do I have two docks in Ubuntu desktop (with GNOME 3) after installing Dash to Dock?

What's going on here? I've installed the Dash to Dock extension on Ubuntu 17.10. Everything was cool, and as I was trying to hone and tweak the look of my desktop, at some point the shortcuts bar (dock?) on the left is duplicated.

^{(Click image to enlarge)}

The default, which normally disappears with Dash to Dock, is there underneath the one that usually shows up when I install Dash to Dock. Why?

I've tried to go through the options for Dash to Dock, the GNOME Tweak Tool, and the regular Ubuntu settings, but I can't figure it out.

Running Dash to Dock along with the default Ubuntu Dock is not a good idea. As Ubuntu Dock is a fork of Dash to Dock (and hence they share many same schemas), issue like this is not really surprising.

Disable one of the two extensions (Ubuntu Dock and Dash to Dock) using Tweaks or in some way (refer to this if you want to disable Ubuntu Dock).

I did the following steps:

• Open Dash to Dock settings
• Got to the 'Poistion and size' tab
• Check the option 'Show on all monitors'

This fixed the problem for me. Hopefully it works for you too. Also make sure Ubuntu dock is disabled.

I have been playing with similar issues: Gnome favorites bar was showing in activities view and dock was showing on lockscreen; as pomsky says, all of this issues are associated with the combination of Ubuntu Dock and Dash to Dock.

I found this workaround for customize the dock with almost all the options that Dash to Dock offers:

1. Install Dash to Dock.
2. Make all your customization.
3. Remove Dash to Dock (from https://extensions.gnome.org/local/).
4. Logout and login.

Although Dash to Dock was removed, the customization (position, size, behavior, appearance) persist on Ubuntu Dock and the issues (docks overlapped, dock shows on lockscreen and favorites shows on activities view) are not present any more.

Notes: with this method, the only thing that you lost from Dash to Dock is the "Dash to Dock settings" menu from the applications icon, and of course, the Dash to Dock settings entry in Gnome Tweak Tool. I haven't tried yet, but I think that if you make a change from Dock entry in Ubuntu settings, may be some customization realized with Dash to Dock settings will be lost.

The following is working for me:

1. Install and configure the "dash to dock" extension

2. Edit the following file:

   sudo vi /usr/share/gnome-shell/extensions/[email protected]/extension.js
   

3. In the following code block, change the let to_enable = true; to let to_enable = false:

   function conditionallyenabledock() {
       let to_enable = false;
       runningExtensions = ExtensionSystem.extensionOrder;
       for (let i = 0; i < runningExtensions.length; i++) {
           if (runningExtensions[i] === "[email protected]") {
               to_enable = false;
           }
       }
   
       // enable or disable dock depending on dock status and to_enable state
       if (to_enable && !dockManager) {
           dockManager = new Docking.DockManager();
       } else if (!to_enable && dockManager) {
           dockManager.destroy();
           dockManager = null;
       }
   }
   

4. Restart your session or do Alt + F2 and type restart

That's it.