Take it easy. Let me tell you how the issue happened. 
If you forget the administrator password and cannot log in to the device, follow the following procedures:
1. Connect to the device using the console port and restart so that the device will start with the default configuration.
2. Then use the default administrator user name/password (admin/Admin@123) to log in to the device.
3. Export the latest configuration file, open the configuration file, and change the administrator password.
4. Upload the modified configuration file back to the device and configure it as the configuration file for the next startup.
5. Restart the device and log in to the device using the new user name and the password.
However, the user still cannot log in to the device as instructed after changing the password.
Please check in the configuration file if there is the manager-user password-modify enable command. If there is such a command in the configuration file, delete it. Then upload the modified configuration file back to the device and configure it as the configuration file for the next startup. Later after restarting the device, you can log in to the device using the new password.
Why so?
Let me explain about this command first.
The manager-user password-modify enable command enables administrator password expiration. If an administrator logs in to the device after password expiration is enabled, the device will prompt the administrator to perform the following operations based on the administrator account and password status:
l If the administrator logs in to the device for the first time after password expiration is enabled, the device prompts the administrator to change the password. Otherwise, the administrator fails to log in.
l When the administrator's password is about to expire in 10 days, the device will prompt the administrator to change the password. The administrator can choose to change the password immediately or continue to log in temporarily without changing the password.
l If the administrator password has expired, the device will prompt the administrator to change the password. Otherwise, the administrator cannot log in.
However, it should be noted that if password expiration is enabled, the password inputted by the administrator is verified against the administrator password stored in the database on the CF card, instead of the password stored in the configuration file. Therefore, if you have enabled this function by mistake, you may not be able to reset the login password by modifying the configuration file.
To disable password expiration, perform the following operations:
<sysname> system-view
[sysname] aaa
[sysname-aaa] undo manager-user password-modify enable
Remember to keep the important information, such as the password, safe after modification.
