Failed to execute login command on FreeBSD

After I deleted slim package with command "pkg delete". And I installed slim back. But when I login to my FreeBSD and the error message comes out as following:

I am sure I enter the right username and password. And I use the root to login, I got the same result.

Solution: Press Keyboard "Ctrl" , "Alt" and "F1" or "F2"  and it will go to the terminal as following:

I can login now.