com.apple.dock.extra quit unexpectedly Error all the time

Have a look at > com.apple.dock.extra quit unexpectedly to see if anything there helps.

Please back up all data before proceeding.

Step 1

In the Finder, hold down the option key and select

Go ▹ Library

from the menu bar. From the Library folder, move the following item to the Trash, if it exists:

Application Support/Dock

and move the following items to the Desktop (again, some may not exist):

Preferences/ByHost/com.apple.dock.*.plist

Preferences/com.apple.dock.db

Preferences/com.apple.dock.plist

Here, * stands for a long string of letters and numbers.

Log out or restart the computer and test. If you still have the issue, put the items on the Desktop back where they came from and go to Step 2. Otherwise, delete the items.

Step 2

This procedure will delete some cache files. The files are automatically generated and don't contain any of your data. Occasionally they can become corrupt and cause problems such as yours.

Please back up all data.

Triple-click anywhere in the line of text below on this page to select it:

open $TMPDIR..

Copy the selected text to the Clipboard by pressing the key combination command-C.

Launch the built-in Terminal application in any one of the following ways:

☞ Enter the first few letters of its name into a Spotlight search. Select it in the results (it should be at the top.)

☞ In the Finder, select Go ▹ Utilities from the menu bar, or press the key combination shift-command-U. The application is in the folder that opens.

☞ Open LaunchPad and start typing the name.

Paste into the Terminal window by pressing command-V. Depending on which web browser you use, you may have to press the return key. A folder with a long, random name should open. Inside it, there should be a subfolder named "C". Drag that to the Trash.

Log out or restart the computer. Empty the Trash. Test.

been following exactly the instructions problem still there...