During language modification > Warning: Cannot modify header..

I made two interface for my society website:

a french one at fatstep.com
and an english one at fatstep.com/en

each interface has its own sql base.

They both have been installed with french version of wordpress, I forgot that i could simply take an english one to make the english interface.

…

Yeah, I know…

In consequence I modified some files to make the registering and the user profil in english but it didn’t work.

Now the english version is broken with these fatal lines that I cannot repair:

Warning: Cannot modify header information – headers already sent by (output started at /homez.99/fatstep/www/en/wp-config.php:1) in /homez.99/fatstep/www/en/wp-content/plugins/theme-my-login/classes/class.wp-login.php on line 38

and

Warning: Cannot modify header information – headers already sent by (output started at /homez.99/fatstep/www/en/wp-config.php:1) in /homez.99/fatstep/www/en/wp-content/plugins/theme-my-login/classes/class.wp-login.php on line 468

Of course I can’t access the dashboard and under internet explorer the view is horrible.

This is the working interface, the french one:
fatstep.com
and the broken one:
fatstep.com/en

I hope I can repair it!