We migrated our site from HTTP to HTTPS. Then we verified our property in search console and submit the new sitemap with HTTPS URLs.

After submission it has the error "Your Sitemap or Sitemap index file doesn't properly declare the namespace."

enter image description here This appears to be because we used https://www.sitemaps.org/schemas/sitemap/0.9 instead of http://www.sitemaps.org/schemas/sitemap/0.9. Is this really important to use the HTTP version of that URL in sitemap? That URL is redirected to HTTPS and google is also supporting HTTPS.

marked as duplicate by Stephen Ostermiller seo Apr 27 '18 at 15:00

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