Could someone have the same error when im trying to register a menu?


function register_my_menu() {
  register_nav_menu('header-menu',__( 'Header Menu' ));
add_action( 'init', 'register_my_menu' );


function register_my_menu() { register_nav_menu('header-menu',__( 'Header Menu' )); } add_action( 'init', 'register_my_menu' ); Warning: Cannot modify header information - headers already sent by (output started at /home/milibyte/public_html/wp-content/themes/test/functions.php:4) in /home/milibyte/public_html/wp-admin/includes/misc.php on line 1126



function register_my_menu() {
    register_nav_menu( 'header-menu',__( 'Header Menu' ) );
add_action( 'after_setup_theme', 'register_my_menu' );
  • is not nesesary to close ? "?>" – fdesu Aug 22 '18 at 22:12
  • Not unless you need to switch over to HTML mode. I never end a file with ?> too often there is a hidden space or too many carrage returns after, and that can cause similar troubles like you had – De Coder Aug 22 '18 at 22:14

The error may display itself when there are:

  • Blank lines at the top or bottom of a document
  • Too many spaces before, in between or after the beginning PHP tags
  • There are too many unneeded spaces or blank lines in a specific part of a document

Just to debug, try to do something like this.

function register_my_menu() { 
     //do nothing 
add_action( 'init', 'register_my_menu' );

If you Google that issue you will get amazed by how many people have that just because of extra spaces or wrong things on the functions.php.

  • but my functions.php is so small!! – fdesu Aug 22 '18 at 21:15
  • It doesn't matter, we just need one character in a wrong position to make it it fails, did you check //do nothing? – Castiblanco Aug 22 '18 at 21:16
  • exist something to check the lines? – fdesu Aug 22 '18 at 21:16
  • ahh sorry, yes i check and the problem persist! – fdesu Aug 22 '18 at 21:17
  • So, we know is something wrong in you functions.php, since it's small you can remove everything and start pasting back small pieces of codes to see when the error shows up again. – Castiblanco Aug 22 '18 at 21:18

I believe you are running your action too soon.

Don't run it at 'init', use 'after_setup_theme' instead.

add_action( 'after_setup_theme', 'register_my_menu' );

  • thanks, but the problem persist. – fdesu Aug 22 '18 at 20:42
  • Do you have php wrappers around the code? If not, that could cause this. – De Coder Aug 22 '18 at 20:52
  • i did, I use notepadd c++ with no BOM and check wrappers. – fdesu Aug 22 '18 at 21:00
  • The way you list the message, it looks like it's spitting out your php code, then saying headers are already sent. This sounds like you did not start the file with <?php – De Coder Aug 22 '18 at 21:05
  • i put it in github. – fdesu Aug 22 '18 at 21:49

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