To verify, try switching to the unedited default Theme (Twenty Seventeen, etc.) using FTP/ SFTP , or a file manager in your hosting account’s control panel (consult your hosting provider’s documentation for specifics on these), navigate to /wp-content/themes/ and switch to the default theme by renaming your current theme’s folder by adding "-old" to the end of the folder name. Alternately, you can remove other themes except the default theme (Twenty Seventeen, etc.). That will force your site to use it.

Error message is still:

Warning: Cannot modify header information – headers already sent by (output started at /nfs/c11/h04/mnt/192717/domains/water.bhfs.com/html/wp-content/themes/bhfsblog/functions.php:151) in /nfs/c11/h04/mnt/192717/domains/water.bhfs.com/html/wp-includes/pluggable.php on line 1216

Would you be able to provide more detailed info on how to change the theme with FTP/SFTP? The link you provided seems to be broken. Or any other way to change the theme to the default without losing existing content?

Thank you!

I recommend reporting the issue to the developers of your theme.

If you need immediate access to dashboard, access your server via FTP/ SFTP , or a file manager in your hosting account’s control panel (consult your hosting provider’s documentation for specifics on these), navigate to /wp-content/themes/ and switch to the default theme by renaming your current theme’s folder by adding "-old" to the end of the folder name. Alternately, you can remove other themes except the default theme (Twenty Seventeen, etc.). That will force your site to use it.