You have unexpected whitespace (either a space or an entire line) on line 1 of the /wp-includes/shortcodes.php file. See this guide for more info.
Alternatively, replacing the file with one from a fresh download may resolve the issue.
Since you already checked the file, I recommend just replacing it with one from a fresh download: https://ww.wp.xz.cn/download/
Hi James,
Thanks for your comment
i tried doing that,however still getting same error. Infant first i removed shortcake.php file and upload it as new then checked it was not woking so i removed pluggable.php as well and uploaded it as new but i don’t know why same error is coming.
“Warning: Cannot modify header information – headers already sent by (output started at /home/admin0902/public_html/wp-includes/shortcodes.php:1) in /home/admin0902/public_html/wp-includes/pluggable.php on line 1228
“
Should i try to replace complete folder of WP_include? will this impact my current website
The error might just be a symptom of a function conflict then.
Try manually resetting your plugins (no Dashboard access required). If that resolves the issue, reactivate each one individually until you find the cause.
If that does not resolve the issue, access your server via SFTP or FTP, or a file manager in your hosting account’s control panel, navigate to /wp-content/themes/ and rename the directory of your currently active theme. This will force the default theme to activate and hopefully rule-out a theme-specific issue (theme functions can interfere like plugins).