1) There is an actual php function get_headers() which you may have misspelt as get_header()
2) You might have created your own function which has been misspelt as get_header()
3) You forgot to include the page that has got this function or you may have changed or deleted the location of this include .
Try to do one thing.. You have mentioned that you didn't get this error in index.php page... This means that you have either included the function properly in index.php or you haven't used it at all
Insert this code somewhere in index.php:
Code:
if (function_exists('get_header'))
{ echo "The function get_header is included in this page" ;}
If you get an output "The function get_header is included in this page" , then check which files you have included in index.php and find out which one you are missing in other pages...
Bookmarks