I changed only the user name on the SMARTDAC+ GX/GP with the advanced Security function (/AS), but the password that I’ve always used to log in doesn’t work anymore. What should I do?

If you change the user name, the password is reset. If you log in with the default password the password change screen appears and you can change to a unique password.

For the default password, see section 2.3, “Logging In and Out" in IM 04L51B01-05EN.