Dark mode stuck on

Please read this whole message before doing anything.

This procedure is a diagnostic test. It won’t solve your problem. Don’t be disappointed when you find that nothing has changed after you complete it.

The purpose of this test is to determine whether the problem is localized to your user account. Enable guest logins* and log in as Guest. Don't use the Safari-only “Guest User” login created by “Find My Mac.”

While logged in as Guest, you won’t have access to any of your documents or settings. Applications will behave as if you were running them for the first time. Don’t be alarmed by this behavior; it’s normal. If you need any passwords or other personal data in order to complete the test, memorize, print, or write them down before you begin.

Test while logged in as Guest. Same problem?

After testing, log out of the guest account and, in your own account, disable it if you wish. Any files you created in the guest account will be deleted automatically when you log out of it.

*Note: If you’ve activated “Find My Mac” or FileVault in OS X 10.7 or later, then you can’t enable the Guest account. The "Guest User" login created by "Find My Mac" is not the same. Create a new account in which to test, and delete it, including its home folder, after testing.

Is the dark effect present in all applications, or only some?

Back up all data before proceeding.

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.

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 restart the computer. Empty the Trash. Test.

If the problem is not solved, open the Library folder again in the same way and move the entire contents of each of the subfolders "Application Support," "Containers," "Group Containers," and "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. Restart again. The account will then be pretty much in a clean state. Test. If you can still reproduce the problem, then put the folder contents back, replacing any that were created in their place, log out, and restart.

To replace a preference file, you may have to move it to the Trash, then put the old one in its place.

If you can't reproduce the problem in the clean state, then start putting things back in the Preferences folder piecemeal, starting with items that seem unrelated to the issue. I can’t be more specific. After each group of items, repeat the log out/log in cycle 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.

Thanks for the update. So that others can benefit from your experience, did you determine which file was causing the problem?

Some third-party applications, such as App Store products, may store documents in a subfolder of the Containers folder, so you should check to make sure you haven't deleted anything you need.

Thank you for your help. I was able to fix the same problem using this guide. In my case, the corrupted files were the following files in "Preferences/ByHost/" folder:

- com.apple.imservice.ids.FaceTime.XXXXX...

- com.apple.imservice.ids.iMessage.XXXXX....

- com.apple.imservice.SMS.XXXXX...