Sumit, I think you have login.htmpl customized for 12.5 and now
after you upgraded to 12.9 you should re-customize this file
using the one from 12.9 install. Please check
\site\mods\www\htmpl\default
and
\site\mods\www\htmpl\web\analyst
to see if you have login.htmpl there and if yes, take a look at its last modified date and you will know what it is.
There is another possibility that you don't clear the browser
cache so as first step please delete/clear browser cached files and see if that helps.
Thanks
Chi