WP:ACC https://en.wikipedia.org/wiki/WP:ACC creates accounts for users having a number of difficulties, many of which have blocks. We have received several emails regarding users attempting to login to their account and receiving an account creation block notice because they are mistyping their username.
An account creation block notice is displayed instead of "Login error: There is no user by the name "xx". Usernames are case sensitive. Check your spelling, or create a new account."
A login error needs to still be displayed to alert the user to check their spelling.