Quick answer
A sitemap is XML.
Sitemap Invalid XML
A sitemap is XML. Invalid XML (unclosed tag, wrong encoding) causes crawlers to reject it.
Common causes
- Unclosed tag.
- Invalid character or encoding.
How to fix
- Validate as XML; fix tags and encoding.
- Use UTF-8 and proper escaping.
FAQ
- Sitemap format?
- XML.
- Encoding?
- UTF-8.
Fix it now
Try in validator (prefill this example)