Can't login to dashboard

Login to your webhost via cpnel, and replace this file
twentyeleven-child/functions.php

with the one before, in case you don’t have a backup of theme files, just manually reverse whatever you had just changed, or just delete that file, and start fresh.

Better switch back to Twenty Eleven theme and see if you can login.

How do i log in with cpnel?
My web host is dreamhost

Login to dreamhost and look for something like file manager (or whatever name they use) and look for the location where WordPress is installed.

FTP is a good way to do this:

https://wiki.dreamhost.com/FTP

https://wiki.dreamhost.com/FileZilla_Setup

Typo: cpnel > cpanel

Dreamhost has its own version of cpanel
https://panel.dreamhost.com/

FTP is good too, but it’s not secure, telling a person to use SFTP is a lot harder than telling him/her to login via cpanel which most webhosts provide via https.

I can access my files with filezilla.
I’m just not sure how to change back to the twentyeleven theme or which files must be changed.
The only change I made previously was to create a twentyelven childs theme and import the parent’s Css style.
It was working fine until this morning when I wasn’t able to log in.

The only change I made previously was to create a twentyelven childs theme and import the parent’s Css style.

So what about the error refering to functions.php in your child ? Did you copy over that file from parent theme to child theme ? If so, it’s wrong.

Try deleting this file
twentyeleven-child/functions.php

and see how it goes.

The problem is resolved.
This is how: I just deleted this file: ‘twentyeleven-child/functions.php’;
like paulwpxp indicated above.
Seems weird though, there was not code there. I just created a functions.php in my child theme because i wanted to make some style changes and was under the impression that using functions was the best way to do so.
Thank you every one for your quick replies and helping my resolve this.