Q: Keychain login problem

Back up all data before proceeding.

Double-click the line below on this page to select it:

com.apple.scopedbookmarksagent.xpc

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

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.

Click in the search field in the upper right corner of the Keychain Access window and press command-V to paste the text you copied earlier. A password item with the above name should appear in the window. Press delete and confirm when prompted. Quit Keychain Access and see whether the prompts have stopped.

Credit for this observation to ASC member bad_friday.

Back up all data before proceeding.

Select the login keychain from the list on the left side of the Keychain Access window. If your default keychain has a different name, select that.

If the lock icon in the top left corner of the window shows that the keychain is locked, click to unlock it. You'll be prompted for the keychain password, which is the same as your login password, unless you've changed it.

Right-click or control-click the login entry in the list. From the menu that pops up, select

          Change Settings for Keychain "login"

In the sheet that opens, uncheck both boxes, if not already unchecked.

From the menu bar, select

          Keychain Access ▹ Preferences... ▹ First Aid

There are four checkboxes in the window that opens. Check all of them. if they're not already checked. Close the window.

Select

          Keychain Access ▹ Keychain First Aid

from the menu bar and repair the keychain. Quit Keychain Access.

If you use iCloud Keychain, open the iCloud preference pane and uncheck the Keychain box. You'll be prompted to delete the local iCloud keychain. Confirm. Then re-check the box. Follow one of the procedures described in this support article to set up iCloud Keychain on an additional device.

I had issues with my keychain and got similar messages when I was getting my smart card (military CAC card) setup.  I was getting popups for not only message agent, but iCloud, FaceTime, etc...I ended up having to trash the keychain folder located at ~/Library/Keychains and start over. 

What are the names of the keychains listed in Keychain Access, besides "login" and "System"?

Remove the Norton/Symantec product by following these instructions. If you have a different version of the product, the procedure may be different.

Back up all data before making any changes. Never install any commercial "anti-virus" or "anti-malware" product again.

Any reason you can't trash the Keychains folder and and allow Keychain to rebuild itself, or do you have way too much stuff logged in there?

Are you sure the "brian" keychain is set to unlock automatically at login? Can you lock it and then unlock it with the login password?

Please take these steps to resynchronize the iCloud keychain. Your keychain on iCloud and your other Apple devices won't be affected. Take Step 2 only if Step 1 doesn't solve the problem.

Step 1

Back up all data.

Open the iCloud preference pane and uncheck the Keychain box. You'll be prompted to delete the local iCloud keychain. Confirm—the data will remain on the servers. Then re-check the box. Follow one of the procedures described in this support article to set up iCloud Keychain on an additional device. Test.

Step 2

If you still have problems, uncheck the Keychain box again and continue.

Triple-click the line below on this page to select it, then copy the text to the Clipboard by pressing the key combination  command-C:

~/Library/Keychains

In the Finder, select

          Go ▹ Go to Folder...

from the menu bar and paste into the box that opens by pressing command-V. You won't see what you pasted because a line break is included. Press return.

A folder named "Keychains" should open. Inside it is a subfolder with a long name similar to (but not the same as) this:

           421DE5CA-D745-3AC1-91B0-CE5FC0ABA128

The above is only an example; yours will have a different name of the same general form. Drag the subfolder (not the Keychains folder) to the Trash and empty.

Restart the computer and re-enable iCloud Keychain.