It seems like something wrong with the login class being used.
Could you please share what is the URL of the application or launchpad you are trying to open and
What is the Logon class specified for the same in SICF settings. It should be "/UI2/CL_SRA_LOGIN".
error on line 493 on login.js could be because of missing field ids "CONFIRM_PASSWORD_FIELD-inner" or "NEW_PASSWORD_FIELD-inner"
go to network tab in the developer tool and check the function " fioriLogin.initChangePasswordForm = function ()" in login.js when it is loaded.
Regards,
Sarbjeet Singh