is there a way to remove the X button from the header ?

this one

GamoCed where exactly do you see that button? Is it inside of the search field? Can you maybe share a large screenshot where we see it in context?

clarkwinkelmann It shows up when you have a welcome message on your forum.

clarkwinkelmann in the welcome banner

button.Hero-close.Button.Button--icon.Button--link.hasIcon{display:none !important;}

giter thanks it worked