El Capitan keychain problem

In the article read the paragraph create new login keychain Change or reset the password of a macOS user account - Apple Support

The default Keychain password is the same as one's user account password. If it isn't the same for whatever reason then see: If your Mac keeps asking for the login keychain password.

Repair Keychain in El Capitan or Sierra

1. Launch Keychain Access (located in Applications/Utilities)
2. Click "Show Keychains" in the lower-left corner of the window.
3. Select the problematic keychain from the left-hand pane.
4. Navigate to the "File" menu and select "Delete Keychain '(name of keychain)'"
5. Check all options for deletion and press "OK"
6. Create a new keychain by going to the "File" menu, then "New" and selecting "New Keychain"
7. You can now make this keychain your default if you desire by selecting it, then going to the "File" menu and selecting "Make '(name of keychain)' Default"

Keychain Issues - Resolve see post by Kappy