Hi Peiyouliao,
I am sorry for the late reply,
I unable to login to your site and it seems you haven't activate our access yet.
Warning
Username and password do not match or you do not have an account yet.
Regarding the publish button on your composer, have you tried clear your site and browser cache? If not, please try clear it first and see how it goes. About the database error, may I know what the error displayed there? Perhaps you can tell us steps on how can we replicate this issue.
Please advise.