error on line 2 at column 6: XML declaration allowed only at the start of the do

Try this

https://www.ads-software.com/support/topic/sitemap-error-xml-declaration-allowed-only-at-the-start-of-the-document

I faced exactly same issue, tried disabling every plugin…changing the theme solved the issue, so it was something in the theme and finally FIXED it by REMOVING THE CLOSING ?> from my parent theme functions.php.
This may help others with the same issue.

Had this exact issue too – as many have mentioned, the issue was held in functions.php. A line break after a PHP tag caused the whole sitemap to fall over – glad it’s sorted now though!

Hi guys,

I have exactly the same issue! When i tried almost everything it still gives the following error:

error on line 3 at column 6: XML declaration allowed only at the start of the document

Can you please help me: