Change to xdmp:user-last-login
The userid parameter has been removed from xdmp:user-last-login. In MarkLogic 8 the xdmp:user-last-login took one parameter (userid). If the userid was different from the current user, the function returned an empty sequence. If the userid was the same as that of the current user, it only returned the last login information.
In MarkLogic 9 the function does not take a parameter. The xdmp:user-last-login function only returns the last login information for the current user.