Aft upgrading to Mac OS X 10.11 El Capitan, too many users face keychain not working correctly. How to fix?
Firstly, if you enable MagicPrefs, it could cause the trouble. Disable it.
Otherwise, take the following steps to solve Keychain Issues: Run Keychain Access (Found in Applications/Utilities) —> Select Preferences from the Keychain Access menu —> Select First Aid tab —> Check on Synchronize login keychain password option —> Close the Preferences window —> Select Keychain First Aid from the Keychain Access menu —> You need to confirm your admin user and password —> Click on Repair button.
Best luck!