Yoast sitemap — error on line 3 at column 6

Hello, I need your help on the plugin.

Sitemap generated with error.
I had several plugins responsible for creating sitemap.xml and I deleted them all.
I deactivated the Sitemap creation features in Yoast SEO, then I activated it.

But when requesting sitemap.xml some kind of error is output:

This page contains the following errors:
error on line 3 at column 6: XML declaration allowed only at the start of the document
Below is a rendering of the page up to the first error.

Please tell me how to achieve the generation of sitemap.xml without errors.
Help me please.

• This topic was modified 4 years, 9 months ago by slavua.