Cannot modify header error

I have this error, before that i have a error with W3 cache plugin, so i have remove the plugin, after that i have this issue and that show only when try to go to admin setion o logging on the blog.

This is the error:

Warning: Cannot modify header information – headers already sent by (output started at /home/content/a/r/i/arismendy4444/html/wp-config.php:1) in /home/content/a/r/i/arismendy4444/html/wp-includes/pluggable.php on line 1207