If your Mac keeps asking for the login keychain password
After you or an ICT Technician resets or changes your account password, your Mac will ask you to update your keychain password or enter the password of your login keychain. It might also tell you that the system was unable to unlock your login keychain.
That's because your login keychain is still using your old password as a security measure to protect saved logins, which could include banking details, etc.
Update your Login Keychain Password
At every login following the update of your password where the keychain password needs to be updated - you will see this window. Please read the options provided by the Mac at this step and take the most suitable action to update or recreate your keychain as necessary.
Continue Log In - You should almost never choose this option as you will continue to be prompted repeatedly for the password to unlock your keychain. Use this option only if you want to keep your keychain details and have a way of retrieving the correct password to unlock it at a later time.
Update Keychain Password - If you know your old (previous) password that was used on the computer prior to changing it, then click the "Update Keychain Password" option and enter your previous password. Be aware that if you don't enter the correct password after this, you will continue to receive keychain prompts.
Create New Keychain - For many students, this will be the best option following a password change. Because students can use various computers and may not have used a particular computer for some time (i.e. in a lab or the Library), the password the computer wants may be the password the student was using two password changes prior and they likely will not know what to enter. Clicking the "Create New Keychain" option will reset the keychain on the computer and stop the keychain prompts.
That didn't work, what now?
If for any reason you are still unable to get rid of the Keychain prompts or are no longer seeing the window providing the option to create a new keychain, which can occur if you choose to update the Keychain Password and enter an incorrect password, then a more direct method may be required to remove the keychain.
The Apple Support article below provides a few additional methods for resolving the login keychain prompts.
If you are still unable to resolve this with any of these methods, please log a Help Desk ticket at firstname.lastname@example.org and an ICT Technician will be able to assist you.