Enhanced Dictation is not working

You didn't copy the whole line. Please review the instructions and try again.

You wrote in your original post that you had deleted a file. What file was that?

Did you take Steps B and C in my earlier comment?

Please back up all data.

Launch the Keychain Access application in any 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.

From the Category list in the lower left corner of the window, select

All Items

Select the entire line below on this page and copy it to the Clipboard (command-C):

com.apple.assistant

Paste (command-V) into the search box in the upper right corner of the Keychain Access window. Delete any items that appear in the search results.

Disable and then reenable Enhanced Dictation. Test.

Please back up all data before proceeding.

Hold down the option key and select

Go ▹ Library

from the Finder menu bar. From the Library folder, move the entire contents of the subfolder "Caches" (not the folder itself) to the Trash, then log out or restart the computer. Empty the Trash. Test.

If the problem is not solved, quit all running applications except the Finder. Open the Library folder again in the same way and move the entire contents of each of the following subfolders

Application Support

Containers

Group Containers

Preferences

(not the folders themselves) to a new folder on the Desktop (not to the Trash.) The "Group Containers" folder exists only in OS X 10.10 and later. Log out again.

The account will then be pretty much in a clean state. Test. If you can still reproduce the problem, then put all the folder contents back, replacing any that were created in their place, and log out.

To replace a preference file, you may have to move it to the Trash, then put the old one in its place. The change may take effect only after logging out.

If you can't reproduce the problem in the clean state, then start putting things back piecemeal, starting with items that seem unrelated to the issue. I can’t be more specific. After each group of items, log out and test. At some point, the problem may reappear, in which case you know that something in the last batch of files you restored is at fault. If it never reappears, the problem is solved.

You're not looking in the right folder. Please follow the instructions exactly. Don't do something else that you think will have the same effect.

You are a genius

Hardly. It took five days to solve the problem. But if it ever comes up again, maybe I will look like genius.